April 23rd...
I think Easter is the following Sunday after Passover.
In 2013, Passover began on the evening of March 25th.
passover 60ad
Passover always begins on the same date on the Hebrew calendar: the 14th of Nissan.
The latest possible date of Easter is April 25.
In 1998, April 11th was Shabbat and also the first day of Passover. It happens, but not very often.
Monday, March 29th at Sundown.
March 25 - April 2 in 2013.
As soon a passover ends, leavened foods are again permissible, subject to other general kosher laws.
As of this date, the latest is Marshall with a Chance.
The fourteenth of Nissan (Numbers ch.9).
April 14 - April 22 in 2014.