Easter

[diddlydi]

If Christmas on the same day every year, why does the date of Easter change?

[bigmamma]

Hope this explains it :-)

http://en.wikipedia.org/wiki/Easter

[pussnboots]

Easter sunday is the first sunday after the first full moon after the vernal equinox. Thats is why it moves, as does the moons phases.

[knobbynonuts]

This might explain as well as sometimes the easter bunny cant attend easter on a regular date as for the fact that he is locked up.
https://www.youtube.com/watch?v=tg-TwaxTPSs

[jno]

broadly speaking, because it arose out of the Jewish calendar, which is based on the moon; so it jumps around as they try to align it with the solar calendar we now use with the help of some really ornate calculations. A bit silly, imho; regular dates are much easier to deal with.

[GGM]

Just a wee correction. Christmas Day does NOT fall on the same day of each year but it DOES fall on the same date. You had me a little confused there.

No need for me to answer your question, as bigmamma and co have already enlightemed you.