Template:Pascha date

(Difference between revisions)

May 1 2016

Usage

This template displays the date of Pascha for the current year.

Usage: {{Pascha date}}

Or this template displays the date of Pascha for the year passed by the year parameter.

Usage: {{Pascha date|year=nnnn}}

where nnnn is the year

Algorithm

The following algorithm is based on the algorithm derived by the German mathematician Gauss. The principal simplification is that substitutions have been made for the case of Julian calendars and Orthodox Easters. This algorithm calculates the number of days AFTER March 21 (Julian) that Easter occurs.

``` RMD(x,y) = remainder when x is divided by y.

R1=RMD(Year,19)
R2=RMD(Year,4)
R3=RMD(Year,7)
RA=19*R1+16
R4=RMD(RA,30)
RB=2*R2+4*R3+6*R4
R5=RMD(RB,7)
RC=R4+R5
```

The number RC ranges from 1 to 35 which corresponds to March 22 to April 25 in the Julian Calendar (currently April 4 to May 8 on the Gregorian). The Julian Calendar is now 13 days behind the Gregorian, and will be until March 1, 2100 when it will be 14 days behind the Gregorian Calendar.