A tropical year or solar year (or tropical period ) is the time that the Sun takes to return to the same position in the sky – as viewed from the Earth or another celestial body of the Solar System – thus completing a full cycle of astronomical seasons . For example, it is the time from vernal equinox to the next vernal equinox, or from summer solstice to the next summer solstice. It is the type of year used by tropical solar calendars .
134-680: The Solar Hijri calendar is the official calendar of Iran . It is a solar calendar and is the one Iranian calendar that is the most similar to the Gregorian calendar, being based on the Earth's orbit around the Sun. It begins on the March equinox as determined by the astronomical calculation for the Iran Standard Time meridian (52.5°E, UTC+03:30 ) and has years of 365 or 366 days. It
268-422: A 25-year cooperation agreement that will strengthen the relations between the two countries and would include "political, strategic and economic" components. Iran-China relations dates back to at least 200 BC and possibly earlier. Iran is one of the few countries in the world that has a good relationship with both North and South Korea . Iran is a member of dozens of international organizations, including
402-405: A "tropical millennium" is decreasing by about 0.06 per millennium (neglecting the oscillatory changes in the real length of the tropical year). This means there should be fewer and fewer leap days as time goes on. A possible reform could omit the leap day in 3200, keep 3600 and 4000 as leap years, and thereafter make all centennial years common except 4500, 5000, 5500, 6000, etc. but the quantity ΔT
536-480: A ceremonial body without any real power. The political system is based on the country's constitution . Iran ranked 154th in the 2022 The Economist Democracy Index . Juan José Linz wrote in 2000 that "the Iranian regime combines the ideological bent of totalitarianism with the limited pluralism of authoritarianism ". The President is head of government and the second highest-ranking authority, after
670-590: A close economic and military alliance, and are subject to heavy sanctions by Western nations. Iran is the only country in Western Asia that has been invited to join the CSTO , the Russia-based international treaty organization that parallels NATO . Relations between Iran and China are strong economically; they have developed a friendly, economic and strategic relationship. In 2021, Iran and China signed
804-869: A cycle. Iran Iran , officially the Islamic Republic of Iran ( IRI ), also known as Persia , is a country in West Asia . It borders Turkey to the northwest and Iraq to the west, Azerbaijan , Armenia , the Caspian Sea , and Turkmenistan to the north, Afghanistan to the east, Pakistan to the southeast, the Gulf of Oman and the Persian Gulf to the south. With a multi-ethnic population of almost 90 million in an area of 1,648,195 km (636,372 sq mi), Iran ranks 17th globally in both geographic size and population . It
938-411: A day less than 365.25 days (365 days, 5 hours, 55 minutes, 12 seconds, or 365.24667 days). Hipparchus used this method because he was better able to detect the time of the equinoxes, compared to that of the solstices. Hipparchus also discovered that the equinoctial points moved along the ecliptic (plane of the Earth's orbit, or what Hipparchus would have thought of as the plane of the Sun's orbit about
1072-542: A distinct political and cultural entity. The Muslim conquest of Persia (632–654) ended the Sasanian Empire and marked a turning point in Iranian history, leading to the Islamization of Iran from the eighth to tenth centuries and the decline of Zoroastrianism . However, the achievements of prior Persian civilizations were absorbed into the new Islamic polity. Iran suffered invasions by nomadic tribes during
1206-501: A duration of 20 minutes longer than the tropical year, because of the precession of the equinoxes . Since antiquity, astronomers have progressively refined the definition of the tropical year. The entry for "year, tropical" in the Astronomical Almanac Online Glossary states: the period of time for the ecliptic longitude of the Sun to increase 360 degrees . Since the Sun's ecliptic longitude
1340-698: A leading world power, though by the 19th century, it had lost significant territory through conflicts with the Russian Empire . The early 20th century saw the Persian Constitutional Revolution and the establishment of the Pahlavi dynasty . Attempts by Mohammad Mosaddegh to nationalize the oil industry led to an Anglo-American coup in 1953 . After the Iranian Revolution , the monarchy was overthrown in 1979 and
1474-503: A moderate position internationally. In 1997, Rafsanjani was succeeded by moderate reformist Mohammad Khatami , whose government advocated freedom of expression , constructive diplomatic relations with Asia and the European Union , and an economic policy that supported a free market and foreign investment. The 2005 presidential election brought conservative populist and nationalist candidate Mahmoud Ahmadinejad to power. He
SECTION 10
#17327720867961608-411: A number of progressively better tables were published that allowed computation of the positions of the Sun, Moon and planets relative to the fixed stars. An important application of these tables was the reform of the calendar . The Alfonsine Tables , published in 1252, were based on the theories of Ptolemy and were revised and updated after the original publication. The length of the tropical year
1742-471: A strong response from Iran, based on their historical and cultural background. Iran has full-control over the islands. Kish island , as a free trade zone , is touted as a consumer's paradise, with malls, shopping centres, tourist attractions, and luxury hotels. Qeshm is the largest island in Iran, and a UNESCO Global Geopark since 2016. Its salt cave, Namakdan, is the largest in the world, and one of
1876-404: Is (as explained above) that it tracks the observed vernal equinox. Some predictive algorithms had been suggested, but were inaccurate due to confusion between the average tropical year (365.2422 days) and the mean interval between spring equinoxes (365.2424 days). These algorithms are not generally used (see Accuracy ). The Ancient Iranian Solar calendar year begins at the start of spring in
2010-418: Is a major regional power , due to its large reserves of fossil fuels , including the world's second largest natural gas supply , third largest proven oil reserves , its geopolitically significant location, military capabilities , cultural hegemony , regional influence, and role as the world's focal point of Shia Islam . The Iranian economy is the world's 23rd-largest by PPP . Iran is a founding member of
2144-599: Is a reformed version of the Julian calendar organized by the Catholic Church and enacted in 1582. By the time of the reform, the date of the vernal equinox had shifted about 10 days, from about March 21 at the time of the First Council of Nicaea in 325, to about March 11. The motivation for the change was the correct observance of Easter. The rules used to compute the date of Easter used a conventional date for
2278-455: Is a simplification of the Jalali calendar , in which the commencement of the month is tied to the sun's passage from one zodiacal sign to the next. The sun is travelling fastest through the signs in early January (Dey) and slowest in early July (Tir). The current time between the March and September equinoxes is about 186 days and 10 hours, the opposite duration about 178 days, 20 hours, due to
2412-452: Is accountable only to the Rahbar. The Court's rulings are final and cannot be appealed. The Assembly of Experts, which meets for one week annually, comprises 86 "virtuous and learned" clerics elected by adult suffrage for 8-year terms. Iran is subdivided into thirty-one provinces ( Persian : استان ostân ), each governed from a local centre, usually the largest local city, which is called
2546-402: Is an international standard. It is a solar calendar that is designed to maintain synchrony with the mean tropical year. It has a cycle of 400 years (146,097 days). Each cycle repeats the months, dates, and weekdays. The average year length is 146,097/400 = 365 + 97 ⁄ 400 = 365.2425 days per year, a close approximation to the mean tropical year of 365.2422 days. The Gregorian calendar
2680-420: Is astronomically accurate year-to-year as opposed to the more fixed Gregorian or Common Era calendar which, averaged out, has the same year length, achieving the same accuracy (a differently patterned calendar of 365 days for three consecutive years plus an extra day in the next year, save for three exceptions to the latter in a 400-year cycle). The start of the year and its number of days remain fixed to one of
2814-523: Is composed of 21 consecutive 128-year grand cycles and a final 132 grand cycle, for a total of 2820 years. The pattern of normal and leap years which began in 1925, will not repeat until the year 4745. The accuracy of the system proposed by Birashk and other recent authors, such as Zabih Behruz, has been thoroughly refuted and shown to be less precise than the traditional 33-year cycle. Each 2820-year great grand cycle proposed by Birashk contains 2137 normal years of 365 days and 683 leap years of 366 days, with
SECTION 20
#17327720867962948-554: Is filled with many festivities and runs a course of 13 days, the last day of which is called siz-dah bedar ("13 to outdoor"). The Dari (Afghan Persian) month names are the signs of Zodiac. They were used in Iran in the early 20th century when the solar calendar was being used. In the Iranian calendar, every week begins on Saturday and ends on Friday. The names of the days of the week are as follows: shanbeh , yekshanbeh , doshanbeh , seshanbeh , chahārshanbeh , panjshanbeh and jom'eh . Yek , do , se , chahār , and panj are
3082-478: Is four times that of Europe's. There are over 200 protected areas to preserve biodiversity and wildlife, with over 30 being national parks . Iran's living fauna includes 34 bat species, Indian grey mongoose , small Indian mongoose , golden jackal , Indian wolf , foxes , striped hyena , leopard , Eurasian lynx , brown bear and Asian black bear . Ungulate species include wild boar , urial , Armenian mouflon , red deer , and goitered gazelle . One of
3216-404: Is given the symbol ♎︎ (because it used to be toward Libra ). Because of the precession of the equinoxes and nutation these directions change, compared to the direction of distant stars and galaxies, whose directions have no measurable motion due to their great distance (see International Celestial Reference Frame ). The ecliptic longitude of the Sun is the angle between ♈︎ and
3350-559: Is in a seismically active area. On average, an earthquake of magnitude seven on the Richter scale occurs once every ten years. Most earthquakes are shallow-focus and can be very devastating, such as the 2003 Bam earthquake . Iran consists of the Iranian Plateau . It is one of the world's most mountainous countries; its landscape is dominated by rugged mountain ranges that separate basins or plateaus . The populous west part
3484-409: Is longer: that tropical year is comparatively short. The "mean tropical year" is based on the mean sun , and is not exactly equal to any of the times taken to go from an equinox to the next or from a solstice to the next. The following values of time intervals between equinoxes and solstices were provided by Meeus and Savoie for the years 0 and 2000. These are smoothed values which take account of
3618-455: Is mandatory for all male citizen aged 18 to serve around 14 months in the IRIAF or IRGC. Tropical year The tropical year is one type of astronomical year and particular orbital period . Another type is the sidereal year (or sidereal orbital period), which is the time it takes Earth to complete one full orbit around the Sun as measured with respect to the fixed stars , resulting in
3752-414: Is measured with respect to the equinox, the tropical year comprises a complete cycle of seasons, and its length is approximated in the long term by the civil (Gregorian) calendar. The mean tropical year is approximately 365 days, 5 hours, 48 minutes, 45 seconds. An equivalent, more descriptive, definition is "The natural basis for computing passing tropical years is the mean longitude of the Sun reckoned from
3886-643: Is sometimes also called the Shamsi calendar and Khorshidi calendar . It is abbreviated as SH , HS or, sometimes as AHSh , while the lunar Hijri calendar (commonly known in the West as the 'Islamic calendar', although both calendars are Islamic) is usually abbreviated as AH . The solar Hijri calendar predominates in Shia Islam whereas the lunar Hijri calendar predominates in Sunni Islam . The first day of
4020-524: Is taken from the Solar Hijri calendar and translates to "Monday" in Persian. The Solar Hijri year begins about 21 March of each Gregorian year and ends about 20 March of the next year. To convert the Solar Hijri year into the equivalent Gregorian year add 621 or 622 years to the Solar Hijri year depending on whether the Solar Hijri year has or has not begun. Its determination of the start of each year
4154-543: Is the sixth-largest country entirely in Asia and one of the world's most mountainous countries. Officially an Islamic republic , Iran has a Muslim-majority population . The country is divided into five regions with 31 provinces . Tehran is the nation's capital , largest city and financial center . A cradle of civilization , Iran has been inhabited since the Lower Palaeolithic . The large part of Iran
Solar Hijri calendar - Misplaced Pages Continue
4288-551: Is the highest judge of the Supreme Court of Iran . The Chief Justice nominates candidates to serve as minister of justice, and the President selects one. The Chief Justice can serve for two five-year terms. The Special Clerical Court handles crimes allegedly committed by clerics , although it has taken on cases involving laypeople . The Special Clerical Court functions independently of the regular judicial framework and
4422-635: Is the most mountainous, with ranges such as the Caucasus , Zagros , and Alborz , the last containing Mount Damavand , Iran's highest point, at 5,610 m (18,406 ft), which is the highest volcano in Asia. Iran's mountains have impacted its politics and economics for centuries. The north part is covered by the lush lowland Caspian Hyrcanian forests , near the southern shores of the Caspian Sea. The east part consists mostly of desert basins, such as
4556-553: The Hijrah in 622 CE , which is the same as the epoch of the Lunar Hijri calendar but as it is a solar calendar , the two calendars' year numbers do not coincide with each other and are slowly drifting apart, being about 43 years apart as of 2023. The first six months (Farvardin–Shahrivar) have 31 days, the next five (Mehr–Bahman) have 30 days, and the last month (Esfand) has 29 days in common years or 30 days in leap years. This
4690-542: The Oxford English Dictionary as / ɪ ˈ r ɑː n / and / ɪ ˈ r æ n / , while American English dictionaries provide pronunciations which map to / ɪ ˈ r ɑː n , - ˈ r æ n , aɪ ˈ r æ n / , or / ɪ ˈ r æ n , ɪ ˈ r ɑː n , aɪ ˈ r æ n / . The Cambridge Dictionary lists / ɪ ˈ r ɑː n / as the British pronunciation and / ɪ ˈ r æ n / as
4824-489: The Army , the head of Supreme National Security Council , and has the power to declare a state of emergency after passage by the parliament. The President is responsible for the implementation of the constitution, and for the exercise of executive powers in implementing the decrees and general policies as outlined by the Rahbar, except for matters directly related to the Rahbar, who has the final say. The President functions as
4958-554: The Caucasus to the Russian Empire following the Russo-Persian Wars . Iran remained a monarchy until the 1979 Iranian Revolution , when it officially became an Islamic republic on 1 April 1979. Since then, Iran has experienced significant political, social, and economic changes. The establishment of the Islamic Republic of Iran led to the restructuring of its political system, with Ayatollah Khomeini as
5092-625: The G-15 , G-24 , G-77 , IAEA , IBRD , IDA , NAM , IDB , IFC , ILO , IMF , IMO , Interpol , OIC , OPEC , WHO , and the UN , and currently has observer status at the WTO . The military is organized under a unified structure, the Islamic Republic of Iran Armed Forces , comprising the Islamic Republic of Iran Army , which includes the Ground Forces , Air Defence Force , Air Force , and Navy ;
5226-639: The Islamic Golden Age . A series of Iranian Muslim dynasties ended Arab rule, revived the Persian language and ruled the country until the Seljuk and Mongol conquests of the 11th to 14th centuries. In the 16th century, the native Safavids re-established a unified Iranian state with Twelver Shi'ism as the official religion . During the Afsharid Empire in the 18th century, Iran was
5360-714: The Islamic Revolutionary Guard Corps , which consists of the Ground Forces , Aerospace Force , Navy , Quds Force , and Basij ; and the Law Enforcement Command (Faraja), which serves an analogous function to a gendarme . While the IRIAF protects the country's sovereignty in a traditional capacity, the IRGC is mandated to ensure the integrity of the Republic, against foreign interference, coups, and internal riots. Since 1925 , it
5494-775: The Kassites , Mannaeans , and Gutians . Georg Wilhelm Friedrich Hegel called the Persians the "first Historical People". The Iranian Empire began in the Iron Age with the rise of the Medes , who unified Iran as a nation and empire in 625 BC. The Achaemenid Empire (550–330 BC), founded by Cyrus the Great , was the largest empire the world had seen, spanning from the Balkans to North Africa and Central Asia . They were succeeded by
Solar Hijri calendar - Misplaced Pages Continue
5628-711: The Kavir Desert , which is the country's largest desert, and the Lut Desert , as well as salt lakes . The Lut Desert is the hottest recorded spot on the Earth's surface, with 70.7 °C recorded in 2005. The only large plains are found along the coast of the Caspian and at the north end of the Persian Gulf, where the country borders the mouth of the Arvand river . Smaller, discontinuous plains are found along
5762-623: The Late Middle Ages and early modern period , negatively impacting the region. Iran was reunified as an independent state in 1501 by the Safavid dynasty , which established Shia Islam as the empire's official religion, marking another turning point in the history of Islam . Iran functioned again as a leading world power, especially in rivalry with the Ottoman Empire . In the 19th century, Iran lost significant territories in
5896-555: The Northern Hemisphere : on the midnight in the interval between the two consecutive solar noons that includes the instant of the March equinox . Hence, the first mid-day is on the last day of one calendar year, and the second mid-day is on the first day ( Nowruz ) of the next year. The first day of the calendar year, Nowruz ("New Day"), is the greatest festival of the year in Iran, Afghanistan, and some surrounding historically Persian-influenced regions. The celebration
6030-600: The Prutenic Tables in 1551, and gave a tropical year length of 365 solar days, 5 hours, 55 minutes, 58 seconds (365.24720 days), based on the length of a sidereal year and the presumed rate of precession. This was actually less accurate than the earlier value of the Alfonsine Tables. Major advances in the 17th century were made by Johannes Kepler and Isaac Newton . In 1609 and 1619 Kepler published his three laws of planetary motion. In 1627, Kepler used
6164-478: The Republic of Azerbaijan (611 km or 380 mi); to the north by the Caspian Sea ; to the northeast by Turkmenistan (992 km or 616 mi); to the east by Afghanistan (936 km or 582 mi) and Pakistan (909 km or 565 mi); to the south by the Persian Gulf and the Gulf of Oman ; and to the west by Iraq (1,458 km or 906 mi) and Turkey (499 km or 310 mi). Iran
6298-646: The Saur Revolution in 1978 took place in the second month of the Solar Hijri calendar (Persian Ordibehesht ; Saur is named after Taurus ). The Solar Hijri calendar has been until recently the official calendar of the government of Afghanistan, and all national holidays and administrative issues were fixed according to the Solar Hijri calendar. However, the Taliban imposed the lunar Hijri calendar in Afghanistan during both periods of their rule. Under
6432-650: The Seleucid , Parthian , and Sasanian Empires , who governed Iran for almost 1,000 years, making Iran a leading power once again. Persia's arch-rival during this time was the Roman Empire and its successor, the Byzantine Empire . Iran endured invasions by the Macedonians , Arabs , Turks , and Mongols . Despite these invasions, Iran continually reasserted its national identity and developed as
6566-560: The South Caucasus . However, they have shared common interests, such as the issue of Kurdish separatism and the Qatar diplomatic crisis . Iran has a close and strong relationship with Tajikistan . Iran has deep economic relations and alliance with Iraq , Lebanon and Syria, with Syria often described as Iran's "closest ally". Russia is a key trading partner, especially in regard to its excess oil reserves. Both share
6700-666: The United Nations , OIC , OPEC , and ECO as well as a current member of the NAM , SCO , and BRICS . Iran is home to 28 UNESCO World Heritage Sites , the 10th highest in the world, and ranks 5th in Intangible Cultural Heritage , or human treasures. The term Iran ' the land of the Aryans ' derives from Middle Persian Ērān , first attested in a 3rd-century inscription at Naqsh-e Rostam , with
6834-417: The eccentricity of Earth's orbit. (These times will change slowly due to precession of the Earth's apsides , becoming inverted after around 11 500 years.) The Iranian Solar calendar produces a five-year leap year interval after about every seven four-year leap year intervals. It usually follows a 33-year subcycle with occasional interruptions by a single 29-year subcycle. The reason for this behaviour
SECTION 50
#17327720867966968-544: The parliament . The Rahbar is the commander-in-chief of the Armed Forces , controls military intelligence and security operations, and has sole power to declare war or peace. The heads of the judiciary, state radio and television networks, commanders of the police and military, and the members of the Guardian Council are all appointed by the Rahbar. The Assembly of Experts is responsible for electing
7102-634: The "year of the Hijrah," and the lunar Hijri calendar is based on lunar months , and dates from the presumed actual "day of the Hijrah". Each of the twelve months of the Hijri calendar corresponds with a zodiac sign , and in Afghanistan the names of the zodiacal signs were used for the months; elsewhere the month names are the same as in the Zoroastrian calendar . The first six months have 31 days,
7236-410: The 12-year cycles of the Chinese-Uighur calendar , which were not officially sanctioned but were commonly used. In 1975, Iranian scholars discovered that this solar calendar was in use as early as the Achaemenid Era. Therefore, the Pahlavi Government, under the orders of Shah Mohammad Reza Pahlavi , changed the epoch of the calendar to be the first year of the reign of Cyrus the Great , rather than
7370-410: The 1970s. A key development in understanding the tropical year over long periods of time is the discovery that the rate of rotation of the earth, or equivalently, the length of the mean solar day , is not constant. William Ferrel in 1864 and Charles-Eugène Delaunay in 1865 predicted that the rotation of the Earth is being retarded by tides. This could be verified by observation only in the 1920s with
7504-806: The 2nd-most powerful person in Iran, was assassinated by the US , heightening tensions between them . Iran retaliated against US airbases in Iraq , the largest ballistic missile attack ever on Americans; 110 sustained brain injuries . Hardliner Ebrahim Raisi ran for president again in 2021 , succeeding Hassan Rouhani . During Raisi's term, Iran intensified uranium enrichment , hindered international inspections, joined SCO and BRICS, supported Russia in its invasion of Ukraine and restored diplomatic relations with Saudi Arabia. In April 2024, Israel's airstrike on an Iranian consulate , killed an IRGC commander. Iran retaliated with UAVs , cruise and ballistic missiles ; 9 hit Israel. Western and Jordanian military helped Israel down some Iranian drones. It
7638-464: The 33-year cycle approximation, move back by one weekday to jump ahead by one 33-year cycle. Similarly, to jump back by one 33-year cycle, move ahead by one weekday. As in the Gregorian calendar, dates move forward exactly one day of the week with each passing year, except if there is an intervening leap day when they move two days. The anchor date 1 Farvardin 1372 is chosen so that its 4th, 8th, ..., 32nd anniversaries come immediately after leap days, yet
7772-399: The American pronunciation. Voice of America 's pronunciation guide provides / ɪ ˈ r ɑː n / . Iran is home to one of the world's oldest continuous major civilizations, with historical and urban settlements dating back to 4000 BC. The western part of the Iranian plateau participated in the traditional ancient Near East with Elam (3200–539 BC), and later with other peoples such as
7906-448: The Earth's orbit being elliptical, using well-known procedures (including solving Kepler's equation ). They do not take into account periodic variations due to factors such as the gravitational force of the orbiting Moon and gravitational forces from the other planets. Such perturbations are minor compared to the positional difference resulting from the orbit being elliptical rather than circular. The mean tropical year on January 1, 2000,
8040-405: The Earth) in a direction opposite that of the movement of the Sun, a phenomenon that came to be named "precession of the equinoxes". He reckoned the value as 1° per century, a value that was not improved upon until about 1000 years later, by Islamic astronomers . Since this discovery a distinction has been made between the tropical year and the sidereal year. During the Middle Ages and Renaissance
8174-415: The Gregorian calendar would be 3 days, 17 min, 33 s behind the Sun after 10,000 years. Aggravating this error, the length of the tropical year (measured in Terrestrial Time) is decreasing at a rate of approximately 0.53 s per century and the mean solar day is getting longer at a rate of about 1.5 ms per century. These effects will cause the calendar to be nearly a day behind in 3200. The number of solar days in
SECTION 60
#17327720867968308-423: The Gregorian calendar. The low-precision extrapolations are computed with an expression provided by Morrison and Stephenson: where t is measured in Julian centuries from 1820. The extrapolation is provided only to show Δ T is not negligible when evaluating the calendar for long periods; Borkowski cautions that "many researchers have attempted to fit a parabola to the measured Δ T values in order to determine
8442-473: The Guardian Council is not needed. The Leader can revert the decisions of the Guardian Council. The constitution gives the council three mandates: veto power over legislation passed by the parliament , supervision of elections and approving or disqualifying candidates seeking to run in local, parliamentary, presidential, or Assembly of Experts elections. The council can nullify a law based on two accounts: being against Sharia (Islamic law), or being against
8576-444: The Guardian Council, and serves as an advisory body to the Supreme Leader, making it one of the most powerful governing bodies in Iran. The Parliament has 207 constituencies, including the 5 reserved seats for religious minorities. The remaining 202 are territorial, each covering one or more of Iran's counties . Iran uses a form of Sharia law as its legal system, with elements of European Civil law . The Supreme Leader appoints
8710-429: The Hijrah of Muhammad, a change that birthed the Shahanshahi calendar . Overnight, the year number changed from 1354 to 2534. The change lasted until the Iranian revolution in 1979, at which time the new Iranian government reverted the epoch to the Hijrah. Afghanistan legally adopted the official Jalali calendar in 1922 but with different month names. Afghanistan uses Arabic names of the zodiacal signs; for example,
8844-515: The Islamic Republic of Iran was established by Ruhollah Khomeini , who became the country's first Supreme Leader . In 1980, Iraq invaded Iran , sparking the eight-year-long Iran–Iraq War , which ended in stalemate. Iran is officially governed as a unitary Islamic republic with a presidential system , with ultimate authority vested in a Supreme Leader. The government is authoritarian and has attracted widespread criticism for its significant violations of human rights and civil liberties. Iran
8978-407: The Persian Gulf and Gulf of Oman have mild winters, and very humid and hot summers. The annual precipitation ranges from 135 to 355 mm (5.3 to 14.0 in). More than one-tenth of the country is forested . About 120 million hectares of forests and fields are government-owned for national exploitation. Iran's forests can be divided into five vegetation regions: Hyrcanian region which forms
9112-435: The Persian words for the numbers one to five. The name for Friday, jom'eh , comes from Arabic ( جمعة .) Jom'eh is sometimes referred to by the native Persian name, ādineh [ɒːdiːne] ( آدینه ). In some Islamic countries, like Iran and Afghanistan, Friday is the weekly holiday. Calculating the day of the week is easy, using an anchor date. One good such date is Sunday, 1 Farvardin 1372, which equals 21 March 1993. Assuming
9246-419: The Rahbar, and has the power to dismiss him on the basis of qualifications and popular esteem. To date, the Assembly of Experts has not challenged any of the Rahbar's decisions nor attempted to dismiss him. The previous head of the judicial system, Sadeq Larijani , appointed by the Rahbar, said that it is illegal for the Assembly of Experts to supervise the Rahbar. Many believe the Assembly of Experts has become
9380-450: The Revolution or Supreme Leadership Authority, is the head of state and responsible for supervision of policy. The president has limited power compared to the Rahbar. Key ministers are selected with the Rahbar's agreement and they have the ultimate say on foreign policy. The Rahbar is directly involved in ministerial appointments for Defence, Intelligence and Foreign Affairs, as well as other top ministries after submission of candidates from
9514-454: The SI second. As a result, the time scales of TT and UT1 build up a growing difference: the amount that TT is ahead of UT1 is known as Δ T , or Delta T . As of 5 July 2022, TT is ahead of UT1 by 69.28 seconds. As a consequence, the tropical year following the seasons on Earth as counted in solar days of UT is increasingly out of sync with expressions for equinoxes in ephemerides in TT. As explained below, long-term estimates of
9648-538: The Solar Hijri calendar and has never done so, despite being part of the Persian-speaking world. The country does, however, celebrate Nowruz, although the official New Year's Day in Tajikistan is 1 January in the Gregorian calendar, which is also the case in other non-Persian speaking Iranian or Turkic communities ranging from Eastern Europe to Western China. The name of Tajikistan's capital, Dushanbe ,
9782-452: The Solar Hijri calendar was the day of the spring equinox, March 18, 622 CE . The calendar is named the "Hijri calendar" because that was the year that Mohammed is believed to have left from Mecca to Medina, which event is referred to as the Hijrah . This year is generally considered by Muslims as the first year of Islam . The ancient Iranian Solar calendar is one of the oldest calendars in
9916-462: The Sun as a function of Terrestrial Time, and this angular speed is used to compute how long it would take for the Sun to move 360°. The above formulae give the length of the tropical year in ephemeris days (equal to 86,400 SI seconds), not solar days . It is the number of solar days in a tropical year that is important for keeping the calendar in synch with the seasons (see below). The Gregorian calendar , as used for civil and scientific purposes,
10050-469: The Sun, measured eastward along the ecliptic. This creates a relative and not an absolute measurement, because as the Sun is moving, the direction the angle is measured from is also moving. It is convenient to have a fixed (with respect to distant stars) direction to measure from; the direction of ♈︎ at noon January 1, 2000 fills this role and is given the symbol ♈︎ 0 . There was an equinox on March 20, 2009, 11:44:43.6 TT. The 2010 March equinox
10184-650: The Supreme Leader. Iran's foreign relations have been shaped by the Iran–Iraq War (1980–1988), ongoing tensions with the United States, and its nuclear program, which has been a point of contention in international diplomacy. In 1989, Akbar Rafsanjani concentrated on a pro-business policy of rebuilding the economy without breaking with the ideology of the revolution. He supported a free market domestically, favoring privatization of state industries and
10318-455: The Supreme Leader. The President is elected by universal suffrage for 4 years. Before elections , nominees to become a presidential candidate must be approved by the Guardian Council . The Council's members are chosen by the Leader, with the Leader having the power to dismiss the president. The President can only be re-elected for one term. The president is the deputy commander-in-chief of
10452-570: The Taliban's first rule from 1996 to 2001 , the lunar Hijri calendar was imposed, thus changing the year overnight from 1375 to 1417. With effect from 1 Muharram 1444 AH (8 Mordad 1401 SH; 30 July 2022 CE) (the Islamic New Year of the lunar Hijri calendar), the Taliban once again imposed the lunar calendar. Thus the year number once again leaped forward, this time from 1401 to 1444. Tajikistan does not use
10586-567: The accompanying Parthian inscription using Aryān , in reference to the Iranians . Ērān and Aryān are oblique plural forms of gentilic nouns ēr- (Middle Persian) and ary- (Parthian), deriving from Proto-Iranian language *arya- (meaning ' Aryan ', i.e. of the Iranians), recognised as a derivative of Proto-Indo-European language *ar-yo- , meaning ' one who assembles (skilfully) ' . According to Iranian mythology ,
10720-749: The accuracy of the mean tropical year. Many new observing instruments became available, including The complexity of the model used for the Solar System must be limited to the available computation facilities. In the 1920s punched card equipment came into use by L. J. Comrie in Britain. For the American Ephemeris an electromagnetic computer, the IBM Selective Sequence Electronic Calculator was used since 1948. When modern computers became available, it
10854-451: The anchor date itself does not immediately follow a leap day. As of 2024 CE, the only official user of the calendar is Iran. On 21 February 1911, the second Iranian parliament adopted as the official calendar of Iran the Jalali sidereal calendar with months bearing the names of the twelve constellations of the zodiac and the years named for the animals of the duodecennial cycle; it remained in use until 1925. The present Iranian calendar
10988-448: The apparent speed of the Sun) varies in its elliptical orbit: faster in the perihelion , slower in the aphelion . The equinox moves with respect to the perihelion (and both move with respect to the fixed sidereal frame). From one equinox passage to the next, or from one solstice passage to the next, the Sun completes not quite a full elliptic orbit. The time saved depends on where it starts in
11122-511: The apparent velocity of the Sun as the Earth revolves in its orbit. The most important such time scale is Universal Time , which is the mean solar time at 0 degrees longitude (the IERS Reference Meridian ). Civil time is based on UT (actually UTC ), and civil calendars count mean solar days. However the rotation of the Earth itself is irregular and is slowing down, with respect to more stable time indicators: specifically,
11256-405: The average year length over the great grand cycle of 365.24219852. This average is just 0.00000026 ( 2.6 × 10 ) of a day shorter than Newcomb 's value for the mean tropical year of 365.24219878 days, but differs considerably more from the mean vernal equinox year of 365.242362 days, which means that the new year, intended to fall on the vernal equinox, would drift by half a day over the course of
11390-736: The capital (Persian: مرکز , markaz ) of that province. The provincial authority is headed by a governor-general ( استاندار ostândâr ), who is appointed by the Minister of the Interior subject to approval of the cabinet . Iran maintains diplomatic relations with 165 countries , but not the United States and Israel —a state which Iran derecognised in 1979. Iran has an adversarial relationship with Saudi Arabia due to different political and ideologies. Iran and Turkey have been involved in modern proxy conflicts such as in Syria , Libya , and
11524-548: The constitution. The Supreme National Security Council (SNSC) is at the top of the foreign policy decisions process. The council was formed during the 1989 Iranian constitutional referendum for the protection and support of national interests, the revolution, territorial integrity and national sovereignty. It is mandated by Article 176 of the Constitution to be presided over by the President . The Leader selects
11658-509: The country, which was succeeded by the Sasanian Empire in the third century AD. Ancient Iran saw some of the earliest developments of writing, agriculture, urbanisation, religion and central government. Muslims conquered the region in the seventh century AD, leading to Iran's Islamization . The blossoming literature , philosophy , mathematics , medicine , astronomy and art became major elements for Iranian civilization during
11792-440: The entire country as Persia , until 1935, when Reza Shah requested the international community to use its native and original name, Iran ; Iranians called their nation Iran since at least 1000 BC. Today, both Iran and Persia are used culturally, while Iran remains mandatory in official use. The Persian pronunciation of Iran is [ʔiːˈɾɒːn] . Commonwealth English pronunciations of Iran are listed in
11926-586: The executive of affairs such as signing treaties and other international agreements, and administering national planning, budget, and state employment affairs, all as approved by the Rahbar. The President appoints ministers, subject to the approval of the Parliament, and the Rahbar, who can dismiss or reinstate any minister. The President supervises the Council of Ministers , coordinates government decisions, and selects government policies to be placed before
12060-401: The gradual mean motion. They could express the mean longitude of the Sun in a polynomial such as: where T is the time in Julian centuries. The derivative of this formula is an expression of the mean angular velocity, and the inverse of this gives an expression for the length of the tropical year as a linear function of T . Two equations are given in the table. Both equations estimate that
12194-509: The green belt of the north side of the country; the Turan region, which are mainly scattered in the center of Iran; Zagros region , which mainly contains oak forests in the west; the Persian Gulf region , which is scattered in the southern coastal belt; the Arasbarani region , which contains rare and unique species. More than 8,200 plant species are grown. The land covered by natural flora
12328-516: The head of the Supreme Court and chief public prosecutor. There are several types of courts, including public courts that deal with civil and criminal cases, and revolutionary courts which deal with certain offences, such as crimes against national security . The decisions of the revolutionary courts are final and cannot be appealed. The Chief Justice is the head of the judicial system and responsible for its administration and supervision. He
12462-498: The legislature. Eight Vice Presidents serve under the President, as well as a cabinet of 22 ministers, all appointed by the president. Presidential and parliamentary candidates must be approved by the 12-member Guardian Council (all members of which are appointed by the Leader) or the Leader, before running to ensure their allegiance. The Leader rarely does the vetting, but has the power to do so, in which case additional approval of
12596-404: The length of the tropical year is to first find an expression for the Sun's mean longitude (with respect to ♈︎), such as Newcomb's expression given above, or Laskar's expression. When viewed over a one-year period, the mean longitude is very nearly a linear function of Terrestrial Time. To find the length of the tropical year, the mean longitude is differentiated, to give the angular speed of
12730-413: The length of the tropical year was found by comparing equinox dates that were separated by many years; this approach yielded the mean tropical year. If a different starting longitude for the Sun is chosen than 0° ( i.e. ♈︎), then the duration for the Sun to return to the same longitude will be different. This is a second-order effect of the circumstance that the speed of the Earth (and conversely
12864-473: The length of the tropical year were used in connection with the reform of the Julian calendar , which resulted in the Gregorian calendar. Participants in that reform were unaware of the non-uniform rotation of the Earth, but now this can be taken into account to some degree. The table below gives Morrison and Stephenson's estimates and standard errors ( σ ) for ΔT at dates significant in the process of developing
12998-450: The magnitude of the deceleration of the Earth's rotation. The results, when taken together, are rather discouraging." One definition of the tropical year would be the time required for the Sun, beginning at a chosen ecliptic longitude, to make one complete cycle of the seasons and return to the same ecliptic longitude. Before considering an example, the equinox must be examined. There are two important planes in solar system calculations:
13132-655: The military or used for wildlife protection, and entry is prohibited or requires a permit. Iran took control of Bumusa , and the Greater and Lesser Tunbs in 1971, in the Strait of Hormuz between the Persian Gulf and Gulf of Oman. Despite the islands being small and having little natural resources or population, they are highly valuable for their strategic location. Although the United Arab Emirates claims sovereignty, it has consistently been met with
13266-441: The most famous animals is the critically endangered Asiatic cheetah , which survives only in Iran. Iran lost all its Asiatic lions and the extinct Caspian tigers by the early 20th century. Domestic ungulates are represented by sheep , goat , cattle , horse , water buffalo , donkey and camel . Bird species like pheasant , partridge , stork , eagles and falcons are native. The Supreme Leader , "Rahbar", Leader of
13400-448: The motion of planets, and atomic clocks. Ephemeris time (ET) is the independent variable in the equations of motion of the Solar System, in particular, the equations from Newcomb's work, and this ET was in use from 1960 to 1984. These ephemerides were based on observations made in solar time over a period of several centuries, and as a consequence represent the mean solar second over that period. The SI second , defined in atomic time,
13534-693: The name comes from Iraj , a legendary king. Iran was referred to as Persia by the West , due to Greek historians who referred to all of Iran as Persís , meaning 'the land of the Persians '. Persia is the Fars province in southwest Iran, the 4th largest province, also known as Pârs . The Persian Fârs (فارس), derived from the earlier form Pârs (پارس), which is in turn derived from Pârsâ ( Old Persian : 𐎱𐎠𐎼𐎿). Due to Fars' historical importance, Persia originated from this territory through Greek in around 550 BC, and Westerners referred to
13668-557: The national budget. All parliamentary candidates and legislation from the assembly must be approved by the Guardian Council . The Guardian Council can and has dismissed elected members of the parliament. The parliament has no legal status without the Guardian Council, and the Council holds absolute veto power over legislation. The Expediency Discernment Council has the authority to mediate disputes between Parliament and
13802-475: The next five have 30 days, and the last month has 29 days in common years but 30 days in leap years . The ancient Iranian New Year's Day, which is called Nowruz , always falls on the March equinox. Nowruz is celebrated by communities in a wide range of countries from the Balkans to Mongolia . Currently the Solar Hijri calendar is officially used only in Iran. The calendar's epoch (first year) corresponds to
13936-558: The observations of Tycho Brahe and Waltherus to produce the most accurate tables up to that time, the Rudolphine Tables . He evaluated the mean tropical year as 365 solar days, 5 hours, 48 minutes, 45 seconds (365.24219 days). Newton's three laws of dynamics and theory of gravity were published in his Philosophiæ Naturalis Principia Mathematica in 1687. Newton's theoretical and mathematical advances influenced tables by Edmond Halley published in 1693 and 1749 and provided
14070-463: The orbit. If the starting point is close to the perihelion (such as the December solstice), then the speed is higher than average, and the apparent Sun saves little time for not having to cover a full circle: the "tropical year" is comparatively long. If the starting point is near aphelion, then the speed is lower and the time saved for not having to run the same small arc that the equinox has precessed
14204-425: The plane of the ecliptic (the Earth's orbit around the Sun), and the plane of the celestial equator (the Earth's equator projected into space). These two planes intersect in a line. One direction points to the so-called vernal, northward, or March equinox which is given the symbol ♈︎ (the symbol looks like the horns of a ram because it used to be toward the constellation Aries ). The opposite direction
14338-420: The precessionally moving equinox (the dynamical equinox or equinox of date). Whenever the longitude reaches a multiple of 360 degrees the mean Sun crosses the vernal equinox and a new tropical year begins". The mean tropical year in 2000 was 365.24219 ephemeris days , each ephemeris day lasting 86,400 SI seconds. This is 365.24217 mean solar days . For this reason, the calendar year is an approximation of
14472-529: The president. Regional policy is directly controlled by the Rahbar, with the Ministry of Foreign Affairs' task limited to protocol and ceremonial occasions. Ambassadors to Arab countries, for example, are chosen by the Quds Force , which directly reports to the Rahbar. The Rahbar can order laws to be amended. Setad was estimated at $ 95 billion in 2013 by Reuters, accounts of which are secret even to
14606-706: The remaining coast of the Persian Gulf, the Strait of Hormuz , and Gulf of Oman. Iranian islands are mainly located in the Persian Gulf. Iran has 102 islands in Urmia Lake , 427 in Aras River , several in Anzali Lagoon , Ashurade Island in the Caspian Sea , Sheytan Island in the Oman Sea and other inland islands. Iran has an uninhabited island at the far end of the Gulf of Oman , near Pakistan. A few islands can be visited by tourists. Most are owned by
14740-619: The secretary of the Supreme Council, and the decisions of the council are effective after the confirmation by the Leader. The SNSC formulates nuclear policy, and would become effective if they are confirmed by the Leader. The legislature , known as the Islamic Consultative Assembly (ICA), Iranian Parliament or "Majles", is a unicameral body comprising 290 members elected for four-years. It drafts legislation, ratifies international treaties , and approves
14874-589: The solar year: the Gregorian calendar (with its rules for catch-up leap days ) is designed so as to resynchronise the calendar year with the solar year at regular intervals. The word "tropical" comes from the Greek tropikos meaning "turn". Thus, the tropics of Cancer and Capricorn mark the extreme north and south latitudes where the Sun can appear directly overhead, and where it appears to "turn" in its annual seasonal motion. Because of this connection between
15008-459: The time between equinoxes (and prevent them from confounding efforts to measure long-term variations) requires precise observations and an elaborate theory of the apparent motion of the Sun. The necessary theories and mathematical tools came together in the 18th century due to the work of Pierre-Simon de Laplace , Joseph Louis Lagrange , and other specialists in celestial mechanics . They were able to compute periodic variations and separate them from
15142-403: The tropical year gets roughly a half second shorter each century. Newcomb's tables were sufficiently accurate that they were used by the joint American-British Astronomical Almanac for the Sun, Mercury , Venus , and Mars through 1983. The length of the mean tropical year is derived from a model of the Solar System, so any advance that improves the solar system model potentially improves
15276-452: The tropical year is 20 min. shorter than the sidereal year. When tropical year measurements from several successive years are compared, variations are found which are due to the perturbations by the Moon and planets acting on the Earth, and to nutation. Meeus and Savoie provided the following examples of intervals between March (northward) equinoxes: Until the beginning of the 19th century,
15410-413: The tropics and the seasonal cycle of the apparent position of the Sun, the word "tropical" was lent to the period of the seasonal cycle . The early Chinese, Hindus, Greeks, and others made approximate measures of the tropical year. In the 2nd century BC Hipparchus measured the time required for the Sun to travel from an equinox to the same equinox again. He reckoned the length of the year to be 1/300 of
15544-400: The two equinoxes, the astronomically important days when day and night each have the same duration. It results in less variability of all celestial bodies when comparing a specific calendar date from one year to others. [REDACTED] Iranian mathematician Ahmad Birashk (1907–2002) proposed an alternative means of determining leap years. Birashk's book came out in 1993, and his algorithm
15678-512: The underpinnings of all solar system models until Albert Einstein 's theory of General relativity in the 20th century. From the time of Hipparchus and Ptolemy, the year was based on two equinoxes (or two solstices) a number of years apart, to average out both observational errors and periodic variations (caused by the gravitational pull of the planets, and the small effect of nutation on the equinox). These effects did not begin to be understood until Newton's time. To model short-term variations of
15812-463: The vernal equinox (March 21), and it was considered important to keep March 21 close to the actual equinox. If society in the future still attaches importance to the synchronization between the civil calendar and the seasons, another reform of the calendar will eventually be necessary. According to Blackburn and Holford-Strevens (who used Newcomb's value for the tropical year) if the tropical year remained at its 1900 value of 365.242 198 781 25 days
15946-424: The very accurate Shortt-Synchronome clock and later in the 1930s when quartz clocks began to replace pendulum clocks as time standards. Apparent solar time is the time indicated by a sundial , and is determined by the apparent motion of the Sun caused by the rotation of the Earth around its axis as well as the revolution of the Earth around the Sun. Mean solar time is corrected for the periodic variations in
16080-573: The west part. The UN Resident Coordinator for Iran, has said that " Water scarcity poses the most severe human security challenge in Iran today". To the west, settlements in the Zagros basin experience lower temperatures, severe winters with freezing average daily temperatures and heavy snowfall. The east and central basins are arid, with less than 200 mm (7.9 in) of rain and have occasional deserts. Average summer temperatures rarely exceed 38 °C (100.4 °F). The southern coastal plains of
16214-451: The world's longest caves. Iran's climate is diverse, ranging from arid and semi-arid , to subtropical along the Caspian coast and northern forests. On the north edge of the country, temperatures rarely fall below freezing and the area remains humid. Summer temperatures rarely exceed 29 °C (84.2 °F). Annual precipitation is 680 mm (26.8 in) in the east part of the plain and more than 1,700 mm (66.9 in) in
16348-470: The world, as well as the most accurate solar calendar in use today. Since the calendar uses astronomical calculation for determining the vernal equinox , it has no intrinsic error. It is older than the lunar Hijri calendar used by the majority of Muslims (known in the West as the Islamic calendar ); though they both count from the Hijrah. The solar Hijri calendar uses solar years and is calculated based on
16482-528: Was 365.242 189 7 or 365 ephemeris days , 5 hours, 48 minutes, 45.19 seconds. This changes slowly; an expression suitable for calculating the length of a tropical year in ephemeris days, between 8000 BC and 12000 AD is where T is in Julian centuries of 36,525 days of 86,400 SI seconds measured from noon January 1, 2000 TT. Modern astronomers define the tropical year as time for the Sun's mean longitude to increase by 360°. The process for finding an expression for
16616-401: Was March 20, 17:33:18.1 TT, which gives an interval - and a duration of the tropical year - of 365 days 5 hours 48 minutes 34.5 seconds. While the Sun moves, ♈︎ moves in the opposite direction. When the Sun and ♈︎ met at the 2010 March equinox, the Sun had moved east 359°59'09" while ♈︎ had moved west 51" for a total of 360° (all with respect to ♈︎ 0 ). This is why
16750-570: Was based on the same apparently erroneous presumptions as used by Zabih Behruz in his book from 1952. Birashk's technique avoids the need to determine the moment of the astronomical equinox, replacing it with a very complex leap year structure. Years are grouped into cycles which begin with four normal years, after which every fourth subsequent year in the cycle is a leap year. Cycles are grouped into grand cycles of either 128 years (composed of cycles of 29, 33, 33, and 33 years) or 132 years, containing cycles of 29, 33, 33, and 37 years. A great grand cycle
16884-511: Was elected to office. Iran has an area of 1,648,195 km (636,372 sq mi). It is the sixth-largest country entirely in Asia and the second-largest in West Asia. It lies between latitudes 24° and 40° N , and longitudes 44° and 64° E . It is bordered to the northwest by Armenia (35 km or 22 mi), the Azeri exclave of Nakhchivan (179 km or 111 mi), and
17018-550: Was first unified as a political entity by the Medes under Cyaxares in the seventh century BC, and reached its territorial height in the sixth century BC, when Cyrus the Great founded the Achaemenid Empire , one of the largest in ancient history . Alexander the Great conquered the empire in the fourth century BC. An Iranian rebellion established the Parthian Empire in the third century BC and liberated
17152-437: Was given as 365 solar days 5 hours 49 minutes 16 seconds (≈ 365.24255 days). This length was used in devising the Gregorian calendar of 1582. In Uzbekistan , Ulugh Beg 's Zij-i Sultani was published in 1437 and gave an estimate of 365 solar days 5 hours 49 minutes 15 seconds (365.242535 days). In the 16th century Copernicus put forward a heliocentric cosmology . Erasmus Reinhold used Copernicus' theory to compute
17286-447: Was intended to agree with the ephemeris second based on Newcomb's work, which in turn makes it agree with the mean solar second of the mid-19th century. ET as counted by atomic clocks was given a new name, Terrestrial Time (TT), and for most purposes ET = TT = International Atomic Time + 32.184 SI seconds. Since the era of the observations, the rotation of the Earth has slowed down and the mean solar second has grown somewhat longer than
17420-648: Was known for his hardline views, nuclearisation, and hostility towards Israel , Saudi Arabia , the UK , the US and other states. He was the first president to be summoned by the parliament to answer questions regarding his presidency. In 2013, centrist and reformist Hassan Rouhani was elected president. In domestic policy, he encouraged personal freedom, free access to information, and improved women's rights. He improved Iran's diplomatic relations through exchanging conciliatory letters. The Joint Comprehensive Plan of Action (JCPOA)
17554-428: Was legally adopted on 31 March 1925, under the early Pahlavi dynasty . The law said that the first day of the year should be the first day of spring in "the true solar year", "as it has been" ever so. It also fixed the number of days in each month, which previously varied by year with the sidereal zodiac . It revived the ancient Persian names, which are still used. It also set the epoch to the Hijrah. It also deprecated
17688-480: Was possible to compute ephemerides using numerical integration rather than general theories; numerical integration came into use in 1984 for the joint US-UK almanacs. Albert Einstein 's General Theory of Relativity provided a more accurate theory, but the accuracy of theories and observations did not require the refinement provided by this theory (except for the advance of the perihelion of Mercury) until 1984. Time scales incorporated general relativity beginning in
17822-658: Was reached in Vienna in 2015, between Iran, the P5+1 ( UN Security Council + Germany) and the EU. The negotiations centered around ending the economic sanctions in exchange for Iran's restriction in producing enriched uranium . In 2018, however, the US under Trump Administration withdrew from the deal and new sanctions were imposed. This nulled the economic provisions, left the agreement in jeopardy, and brought Iran to nuclear threshold status . In 2020, IRGC general, Qasem Soleimani ,
17956-642: Was the largest drone strike in history, biggest missile attack in Iranian history, its first ever direct attack on Israel and the first time since 1991 , Israel was directly attacked by a state force. This occurred during heightened tensions amid the Israeli invasion of the Gaza Strip . In May 2024, President Raisi was killed in a helicopter crash , and Iran held a presidential election in June, when reformist and former Minister of Health , Masoud Pezeshkian ,
#795204