Calendar

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2020 in various calendars
Gregorian calendar2020
MMXX
Ab urbe condita2773
Armenian calendar1469
ԹՎ ՌՆԿԹ
Assyrian calendar6770
Bahá'í calendar176–177
Balinese saka calendar1941–1942
Bengali calendar1427
Berber calendar2970
British Regnal year68 Eliz. 2 – 69 Eliz. 2
Buddhist calendar2564
Burmese calendar1382
Byzantine calendar7528–7529
Chinese calendar己亥(Earth Pig)
4716 or 4656
    — to —
庚子年 (Metal Rat)
4717 or 4657
Coptic calendar1736–1737
Discordian calendar3186
Ethiopian calendar2012–2013
Hebrew calendar5780–5781
Hindu calendars
 - Vikram Samvat2076–2077
 - Shaka Samvat1941–1942
 - Kali Yuga5120–5121
Holocene calendar12020
Igbo calendar1020–1021
Iranian calendar1398–1399
Islamic calendar1441–1442
Japanese calendarReiwa 2
(令和2年)
Javanese calendar1953–1954
Juche calendar109
Julian calendarGregorian minus 13 days
Korean calendar4353
Minguo calendarROC 109
民國109年
Nanakshahi calendar552
Thai solar calendar2563
Tibetan calendar阴土猪年
(female Earth-Pig)
2146 or 1765 or 993
    — to —
阳金鼠年
(male Iron-Rat)
2147 or 1766 or 994
Unix time1577836800 – 1609459199

A calendar is a tool for organizing days. People use calendars to say when something happened, and for planning things that have not happened yet. The calendar gives the days names and numbers, called calendar dates. The dates are usually made based on how things in the sky seem to move. The year and month are based on motions of the Sun and moon. By knowing what day something happened or will happen, people have an easier life. Since the beginning of history, knowing when the seasons would start for crops was very important for farmers and people who eat.

Calendar systems have a beginning time or era. The calendar era is often a religion-based event, such as the birth of Jesus, but it may be a political event such as a coronation or the founding of a state. Dates that are counted from the coronation are called "regnal".

The three principal calendars most used today are the Gregorian, Hebrew, and Islamic calendars. Other calendar systems from many different parts of the world are also used.

Basis[change | change source]

Calendars are based on three natural things:

  1. The Earth turns all the way around its axis.
  2. The Moon goes all the way around the Earth.
  3. The Earth goes all the way around the Sun.

The Earth turns all the way around its axis about 24 hours. It is called the Solar Day. Days of most calendars are strongly based on the Solar Day.

The Moon turns all the way around the Earth about 29 days, 12 hours, 44 minutes and 2 seconds. Months of some calendars are still strongly based on the Moon. These are called Lunar calendars, which lasts about 354-355 days. Solar calendars ignore the moon, and depend entirely on the Sun.

The Earth goes all the way around the Sun in about 365 days, 5 hours, 48 minutes and 46 seconds. This is called the Tropical Year. Years of most calendars are strongly based on the Tropical Year.

Related pages[change | change source]

Other websites[change | change source]