Easter Dates

 
Gregorian calendar
For Dates after Oct 25, 1582		 Julian calendar
For Dates prior to Oct 15, 1582
  Year :
Year :
 
 

Defined as:

  1. The Sunday that follows
  2. The Friday after
  3. The First Full Moon after
  4. The Vernal Equinox.

Gauß's formulas modified for the calculation of the date of Easter in the year Y of the Gregorian Calendar are given here. Note the modulus are based on the number of days of week, month, number of years in leap year cycle and number of years in leap century cycles, 1900 not a leap year, and 4 century leaps, i.e. 1600, 2000, 2400 are leap years.

a=Ymod19
b=Ymod4
c=Ymod7
d=[19 × (a + 15)]mod30
e=[ 2 × ( b + 4) × ( c + 6 ) × ( d + 6 ) ]mod7
  1. The date of Gregorian Easter is:
  2. ( d + e + 22 ) for March or,
  3. ( d + e  -  9 ) for April.  
    1. note: Negative numbers and numbers larger than 31 for March or 30 for April are meaningless, use alternate month's value
    2. List of Easter dates, 600 years
    3. Kids Math