UT date and time of equinoxes and solstices on the earth [1] |
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event | Northward equinox |
Northern solstice |
Southward equinox |
Southern solstice |
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month | March | June | September | December | ||||
year | ||||||||
day | time | day | time | day | time | day | time | |
2010 | 20 | 17:32 | 21 | 11:28 | 23 | 03:09 | 21 | 23:38 |
2011 | 20 | 23:21 | 21 | 17:16 | 23 | 09:04 | 22 | 05:30 |
2012 | 20 | 05:14 | 20 | 23:09 | 22 | 14:49 | 21 | 11:12 |
2013 | 20 | 11:02 | 21 | 05:04 | 22 | 20:44 | 21 | 17:11 |
2014 | 20 | 16:57 | 21 | 10:51 | 23 | 02:29 | 21 | 23:03 |
2015 | 20 | 22:45 | 21 | 16:38 | 23 | 08:20 | 22 | 04:48 |
2016 | 20 | 04:30 | 20 | 22:34 | 22 | 14:21 | 21 | 10:44 |
2017 | 20 | 10:28 | 21 | 04:24 | 22 | 20:02 | 21 | 16:28 |
2018 | 20 | 16:15 | 21 | 10:07 | 23 | 01:54 | 21 | 22:23 |
2019 | 20 | 21:58 | 21 | 15:54 | 23 | 07:50 | 22 | 04:19 |
2020 | 20 | 03:50 | 20 | 21:44 | 22 | 13:31 | 21 | 10:02 |
The Northward equinox (or March equinox) is the equinox on the earth when the Sun appears to cross the celestial equator, heading northward. The Northward equinox is known as the vernal equinox in the Northern Hemisphere, and the autumnal equinox in the Southern Hemisphere.
The equinox can be as early as March 19 or as late as March 21, the precise time being about 5 hours 49 minutes later in a common year, and about 18 hours 11 minutes earlier in a leap year, than in the previous year. It is the balance of common years and leap years that keeps the calendar date of the equinox from drifting more than a day from 20 March each year.
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Northward equinox solar year
The Northward equinox is one point in time commonly used to determine the length of the tropical year. The length of Northward equinox solar year is relatively stable in the time from 6000 BC to 10000 CE at 47:37 to 49:20 in excess of 365 days and 5 hours.[2]
When tropical year measurements from several successive years are compared, variations are found which are due to nutation, and to the planetary perturbations acting on the Sun. Meeus and Savoie (1992, p. 41) provided the following examples of intervals between northward equinoxes:
min | s | |
---|---|---|
1985–1986 | 48 | 58 |
1986–1987 | 49 | 15 |
1987–1988 | 46 | 38 |
1988–1989 | 49 | 42 |
1989–1990 | 51 | 06 |
Occurrences
Date and time in Universal Time of the March equinox [3]
- 2000-03-20 07:35
- 2001-03-20 13:31
- 2002-03-20 19:16
- 2003-03-21 01:00
- 2004-03-20 06:49
- 2005-03-20 12:33
- 2006-03-20 18:26
- 2007-03-21 00:07
- 2008-03-20 05:48
- 2009-03-20 11:44
- 2010-03-20 17:32
- 2011-03-20 23:21
- 2012-03-20 05:14
- 2013-03-20 11:02
- 2014-03-20 16:57
- 2015-03-20 22:45
- 2016-03-20 04:30
- 2017-03-20 10:28
- 2018-03-20 16:15
- 2019-03-20 21:58
- 2020-03-20 03:50
Constellation
The point where the Sun crosses the celestial equator northwards is called the first point of Aries. However, due to the precession of the equinoxes, this point is no longer in the constellation Aries, but rather in Pisces. By the year 2600 it will be in Aquarius (hence the phrase "the dawning of the Age of Aquarius").
- The Northward equinox passed from Taurus into Aries in year −1865, passed into Pisces in year −67, will pass into Aquarius in year 2597, will pass into Capricornus in year 4312. It passed along (but not into) a 'corner' of Cetus on 0°10' distance in year 1489.
Apparent movement of the Sun in relation to the horizon
At the equinox, the Sun rises directly in the east and sets directly in the west. However, because of refraction it will usually appear slightly above the horizon at the moment when its "true" middle is rising or setting. For viewers at the north or south poles, it moves virtually horizontally on or above the horizon, not obviously rising or setting apart from the movement in "declination" (and hence altitude) of a little under a half (0.39) degree per day.
For observers in either hemisphere not at the poles, the further one goes in time away from the March equinox in the 3 months before that equinox, the more to the south the Sun has been rising and setting, and for the 3 months afterwards it rises and sets more and more to the north.
Human culture
Calendars
The Persian Calendar begins each year at the Northward equinox, observationally determined at Tehran.[4]
The Indian National Calendar starts the year on March 22 (March 21 in leap years) with a 30-day month (31 days in leap years), then has 5 months of 31 days followed by 6 months of 30 days.[5]
Julian calendar
The Julian calendar reform lengthened seven months and replaced the intercalary month with an intercalary day to be added every four years to February. It was based on a length for the year of 365 days and 6 hours (365.25 d), while the tropical year is about 11 minutes and 14 seconds less than that. This had the effect of adding about three quarters of an hour every four years. The effect accumulated from 325 until by the 16th century, when the northern vernal equinox fell on March 10 or 11.
The date in 1452 was March 20 11:52 (Gregorian) and March 11 11:52 (Julian) [6] In 2547 it will be March 20 21:18 (Gregorian) and March 03 21:18 (Julian) [7].
Commemorations
- Abrahamic tradition
- The Jewish Passover usually falls on the first full moon after the Northern Hemisphere vernal equinox, although occasionally (7 times every 19 years) it will occur on the second full moon.[citation needed]
- The Christian churches calculate Easter as the first Sunday after the first full moon on or after the March equinox. The official church definition for the equinox is March 21; however, as the Eastern Orthodox Churches use the older Julian calendar, while the Western Churches use the Gregorian calendar, both of which designate March 21 as the equinox, the actual date of Easter differs. The earliest possible Easter date in any year is therefore March 22 on each calendar. The latest possible Easter date in any year is April 25.[8]
- West Asia
- The Northward equinox marks the first day of various calendars including the Iranian calendar. The ancient Iranian new year's festival of Nowruz can be celebrated March 20 or March 21. According to the ancient Persian mythology Jamshid, the mythological king of Persia, ascended to the throne on this day and each year this is commemorated with festivities for two weeks. These festivities recall the story of creation and the ancient cosmology of Iranian and Persian people. It is also a holiday celebrated in Azerbaijan, Afghanistan, Pakistan, Turkey, Zanzibar, Albania, and various countries of Central Asia, as well as among the Kurds. As well as being a Zoroastrian holiday, it is also a holy day for adherents of the Bahá'í Faith and the Nizari Ismaili Muslims.[9] The Bahá'í Naw-rúz is stationary; the new year always starts at sunset March 20.[10]
- Sham El Nessim was an ancient Egyptian holiday which can be traced back as far as 2700 BC. It is still one of the public holidays in Egypt. Sometime during Egypt's Christian period (c. 200–639) the date moved to Easter Monday, but before then it coincided with the vernal equinox.
- In many Arab countries, Mother's Day is celebrated on the Northward equinox.
- South and Southeast Asia
According to the sidereal solar calendar, celebrations which originally coincided with the Vernal Equinox now take place throughout South Asia and parts of Southeast Asia on the day when the sun enters the sidereal Aries, generally around 14 April.
- It marks the beginning of the new year of the Tamil calendar and is celebrated in the South Indian state of Tamil Nadu
- This day is celebrated as the last day of the year according to the Bengali calendar and Assamese calendar in West Bengal, Assam, Tripura, Bangladesh and throughout the Eastern and North Eastern India. The day is known as Chaitra Sankranti in Bengali. The following is celebrated as the Bengali New Year's Day and Assamese Bihu.
- Andhra Pradesh, Karnataka and Maharastra people celebrate new year ugadi set by Satavahana on the first morning after first new moon from the sidereal vernal equinox. Also the calculations of the great Indian Mathematician Bhaskaracharya proclaim the Ugadi day as the beginning of the New Year, New month and New day.
- In the Indian states Orissa, this day is celebrated as the new year around April 14. It is known as 'Vishuva Sankranti' (meaning "equal" in Sanskrit). In Kerala though the new year is on Chingam 1, the beginning of sidereal zodiac Leo, sidereal vernal equinox is celebrated much more than new year as 'Vishu'
- The traditional New Year celebrations in Cambodia, Laos, Myanmar and Thailand take place on 13 to 15 (or 16) April.
- East Asia
- The traditional East Asian calendars divide a year into 24 solar terms (节气, literally "climatic segments"), and the vernal equinox (Chūnfēn, Chinese and Japanese: 春分; Korean: 춘분; Vietnamese: Xuân phân) marks the middle of the spring. In this context, the Chinese character 分 means "(equal) division" (within a season).
- In Japan, Vernal Equinox Day (春分の日 Shunbun no hi) is an official national holiday, and is spent visiting family graves and holding family reunions.
- Europe
- Lieldienas
- in Norse paganism, a Dísablót was celebrated on vernal equinox.[11]
- Modern culture
- World Storytelling Day is a global celebration of the art of oral storytelling, celebrated every year on the spring equinox in the northern hemisphere, the first day of autumn equinox in the southern.
- World Citizen Day occurs on the Northward equinox.[12]
- In Annapolis, Maryland in the United States, boatyard employees and sailboat owners celebrate the spring equinox with the Burning Of The Socks festival. Traditionally, the boating community wears socks only during the winter. These are burned at the approach of warmer weather, which brings more customers and work to the area. Officially, nobody then wears socks until the next equinox.[13][14]
- Neopaganism - see: Wheel of the Year#Eight_festivals
- International Astrology Day
External links
- "Ancient Equinox Alignment". Loughcrew, Ireland. http://www.knowth.com/loughcrew-equinox.htm.
References
- ^ United States Naval Observatory (2010-06-10). "Earth's Seasons: Equinoxes, Solstices, Perihelion, and Aphelion, 2000-2020". http://www.usno.navy.mil/USNO/astronomical-applications/data-services/earth-seasons.
- ^ http://individual.utoronto.ca/kalendis/leap/Solar-Year-Length-Variations.pdf
- ^ http://www.usno.navy.mil/USNO/astronomical-applications/data-services/earth-seasons
- ^ http://individual.utoronto.ca/kalendis/seasons.htm
- ^ http://individual.utoronto.ca/kalendis/seasons.htm
- ^ http://ns1763.ca/equinox/vern1452-1811.html
- ^ http://ns1763.ca/equinox/vern2188-2547.html
- ^ Cooley, Keith (2001). "Keith's Moon Facts". Hiwaay.net personal pages. http://home.hiwaay.net/~krcool/Astro/moon/.
- ^ "Navroz". The Ismaili. Islamic Publications Limited. http://www.theismaili.org/cms/232/Navroz. Retrieved 2011-07-04.
- ^ "With Spring comes the Baha'i New Year". Bahai.us. National Spiritual Assembly of the Baha'is of the United States. http://www.bahai.us/2011/03/20/with-spring-comes-the-bahai-new-year/. Retrieved 2011-07-04.
- ^ "Disablót". Nationalencyklopedin (Swedish).
- ^ "The utmost global citizen". Global Culture (2007).
- ^ "Annapolis Welcomes Spring by Burning Socks". First Coast News.[not in citation given]
- ^ Rey, Diane. "Hillsmere Joins in Sock Burning Tradition". Annapolis, MD: The Capital. http://www.hometownannapolis.com/news/can/2011/03/25-08/Around-Annapolis-Hillsmere-joins-in-sock-burning-tradition.html. Retrieved 25 April 2011.