St. Gallen, Stiftsbibliothek, Codex Sangallensis 378 (11th century) p. 28. Contains the poem Nonae Aprilis norunt quinos. The reason for this is that Easter must occur after the biblical festival of Passover, on the full moon, when Jesus was crucified,” said Professor Sacha Stern, head of the Hebrew and Jewish Studies department at University College London. German Protestant states used an astronomical Easter between 1700 and 1776, based on the Rudolphine Tables of Johannes Kepler, which were in turn based on astronomical positions of the Sun and Moon observed by Tycho Brahe at his Uraniborg observatory on the island of Ven, while Sweden used it from 1739 to 1844. This astronomical Easter was the Sunday after the full moon instant that was after the vernal equinox instant using Uraniborg time ( TT + 51 m). However, it was delayed one week if that Sunday was the Jewish date Nisan 15, the first day of Passover week, calculated according to modern Jewish methods. [27]

The English word Easter, which parallels the German word Ostern, is of uncertain origin. One view, expounded by the Venerable Bede in the 8th century, was that it derived from Eostre, or Eostrae, the Anglo-Saxon goddess of spring and fertility. This view presumes—as does the view associating the origin of Christmas on December 25 with pagan celebrations of the winter solstice—that Christians appropriated pagan names and holidays for their highest festivals. Given the determination with which Christians combated all forms of paganism (the belief in multiple deities), this appears a rather dubious presumption. There is now widespread consensus that the word derives from the Christian designation of Easter week as in albis, a Latin phrase that was understood as the plural of alba (“dawn”) and became eostarum in Old High German, the precursor of the modern German and English term. The Latin and Greek Pascha (“Passover”) provides the root for Pâques, the French word for Easter. The date of Easter and its controversies An act for regulating the commencement of the year; and for correcting the calendar now in use Statutes at Large 1765, with Easter tables Easter is only ever celebrated by all Christians on the relatively rare occasions when the two calendars align,” she added.

Why does Easter change every year?

Seasons calculator". Time and Date AS. 2014. Archived from the original on 23 March 2019 . Retrieved 23 March 2019. What's everyone talking about? Sign up for our trending newsletter to get the latest news of the day.

Swerdlow, Noel M. (1986). "The Length of the Year in the Original Proposal for the Gregorian Calendar". Journal for the History of Astronomy. 17 (49): 109–118. Bibcode: 1986JHA....17..109S. doi: 10.1177/002182868601700204. S2CID 118491152. Easter is just a hop around the corner – with millions of people around the world are preparing to celebrate this Sunday.

When is Easter 2021?

Bede (1907) [731]. Bede's Ecclesiastical History of England. Translated by Sellar, A. M.; Giles, J. A. London: George Bell and Sons. Archived from the original on 12 May 2019 . Retrieved 23 March 2019– via Project Gutenberg. The present mapping, valid from 1900 to 2199, gives Easter dates with highly varying frequencies. March 22 can never occur, whereas March 31 occurs 13 times in this 300-year span. Nothaft, C. Philipp E. (2018). Scandalous Error: Calendar Reform and Calendrical Astronomy in Medieval Europe. Oxford University Press. ISBN 978-0-19-879955-9. Archived from the original on 9 April 2023 . Retrieved 27 November 2020.

Grotefend, Hermann (1891). Zeitrechnung des deutschen Mittelalters und der Neuzeit. Hahn. Archived from the original on 9 April 2023 . Retrieved 27 November 2020. The earliest known Roman tables were devised in 222 by Hippolytus of Rome based on eight-year cycles. Then 84-year tables were introduced in Rome by Augustalis near the end of the 3rdcentury. [a] Although a process based on the 19-year Metonic cycle was first proposed by Bishop Anatolius of Laodicea around 277, the concept did not fully take hold until the Alexandrian method became authoritative in the late 4th century. [b] On the fortieth day there has from the late fourth century been a particular celebration of Christ’s ascension. He commissions his disciples to continue his work, he promises the gift of the Holy Spirit, and then he is no longer among them in the flesh. The ascension is therefore closely connected with the theme of mission. The arrival of the promised gift of the Holy Spirit on the day of Pentecost completes and crowns the Easter Festival. Seasonal Material The English word Easter, which parallels the German word Ostern, is of uncertain origin.It likely derives from the Christian designation of Easter week as in albis, a Latin phrase that was understood as the plural of alba (“dawn”) and became eostarum in Old High German. The Latin and Greek Pascha (“Passover”) provides the root for Pâques, the French word for Easter.

Previous Years

a b c d e f Davison, Michael E. (1980). "The Frequency Distribution of the Dates of Easter". The Irish Astronomical Journal. 14: 156–164. Bibcode: 1980IrAJ...14..156D. Archived from the original on 9 April 2023 . Retrieved 17 May 2022. The first part consists of determining the variable d, the number of days (counting from 22 March) to the day after the full moon. The formula for d contains the terms 19 a and the constant M. a is the year's position in the 19-year lunar phase cycle, in which by assumption the moon's movement relative to Earth repeats every 19 calendar years. In older times, 19 calendar years were equated to 235 lunar months (the Metonic cycle), which is remarkably close since 235 lunar months are approximately 6939.6813 days and 19 years are on average 6939.6075 days. Gibson, Margaret Dunlop, The Didascalia Apostolorum in Syriac, Cambridge University Press, London, 1903. Lange, Ludwig (1928). "Paradoxe" Osterdaten im Gregorianischen Kalender und ihre Bedeutung für die moderne Kalender reform von Ludwig Lange. Vorgelegt von Eduard Schwartz am 7. Juli 1928. Bayer. Akad. d. Wissenschaften. Archived from the original on 9 April 2023 . Retrieved 27 November 2020.

Easter Sunday is the Sunday following the paschal full moon date. The paschal full moon date is the ecclesiastical full moon date on or after 21 March. The Gregorian method derives paschal full moon dates by determining the epact for each year. [36] The epact can have a value from * (0 or 30) to 29 days. It is the age of the moon in days (i.e. the lunar date) on 1 January reduced by one day. In his book The Easter computus and the origins of the Christian era Alden A Mosshammer incorrectly [ according to whom?] states "Theoretically, the epact 30 = 0 represents the new moon at its conjunction with the sun. The epact of 1 represents the theoretical first visibility of the first crescent of the moon. It is from that point as day one that the fourteenth day of the moon is counted". [37] Early Christians celebrated, therefore,every Sunday like it was Easter. There was no annual commemoration of Easter early on, but by the second and third centuries, there comes to be an annual celebration of Easter,"O'Malley continued, adding that the celebration later grew. In medieval western Europe, the dates of the paschal full moon (14 Nisan) given above could be memorized with the help of a 19-line alliterative poem in Latin: [63] [64] Nonae Aprilis Then Easter Day is the first Sunday after the first ecclesiastical full moon on or after 21 March. (This definition uses "on or after 21 March" to avoid ambiguity with historic meaning of the word "after". In modern language, this phrase simply means "after 20 March". The definition of "on or after 21 March" is frequently incorrectly abbreviated to "after 21 March" in published and web-based articles, resulting in incorrect Easter dates.)

The ratios of (mean solar) days per year and days per lunation change both because of intrinsic long-term variations in the orbits, and because the rotation of the Earth is slowing down due to tidal deceleration, so the Gregorian parameters become increasingly obsolete. In his Kalendarium of 1474, Regiomontanus computed the exact time of all conjunctions of the Sun and Moon for the longitude of Nuremberg according to the Alfonsine Tables for the period from 1475 to 1531. In his work he tabulated 30 instances where the Easter of the Julian computus disagreed with Easter computed using astronomical New Moon. In eighteen cases the date differed by a week, in seven cases by 35 days, and in five cases by 28 days. [66]