Calculation of Easter Sunday online for year 2021

ItemFormulaResult
Golden numbergn = (year % 19) + 18
Julian epactje = 11 × gn % 3028
Centuryce = year / 100 + 121
Solar correctionsc = 3 × (ce - 16) / 43
Lunar correctionlc = 8 × (ce - 15) / 251
Gregorian epactge = (je - 10 - sc + lc) % 3016
March date of Ecclesiastical full moon
(Click here for show conversion table)
for ge <= 23: fm = 44 - ge28
for ge = 24: fm = 49
for ge = 25 and gn < 12: fm = 49
for ge = 25 and gn >= 12: fm = 48
for ge >= 26: fm = 74 - ge
date of Ecclesiastical full moonMarch 28
Gregorian correctiongc = 10 + sc13
Day of week for Ecclesiastical full moon
The number 0 is Sunday, 1 is Monday, and so on until 6, which is Saturday
dfm = (year + year / 4 - gc + fm) % 70
March date of the first Sunday after the Ecclesiastical full moones = fm + (7 - dfm)35
Easter Sunday falls on the first Sunday after the Ecclesiastical full moonApril 4