Calculating the date of Easter
n"Easter day, on
which the rest of the movable
feasts depend, is always the first Sunday
after the fourteenth day of the calendar
moon which (fourteenth day) falls on,
or next after, the 21st of March, according
to the rules laid down for the construction
of the calendar; so that if the fourteenth
day happen on a Sunday, Easter day
is the Sunday after."
- Webster's Revised Unabridged Dictionary (1913)