Easter, Passover, Gobbledygook

Have you ever wondered why it is so difficult to predict when Easter falls each year?
Well, it turns out that Easter Sunday is always the Sunday following the Paschal Full Moon (PFM) date for the year. Since 325 AD, the the Paschal Full Moon has always been the first Ecclesiastical Full Moon (EFM) date after March 20 (which was the spring equinox date in 325 AD). There were some complications arising when most of the western world switched from the old Julian calendar to the current Gregorian calendar (with it's leap years and those missing 10 days), but generally speaking that still narrows down Easter to somewhere between March 21 and April 25th. Just to be difficult, Orthodox Churches insist on using the Julian calendar and their Easter is usually a week or two later.
Simple, eh? Well, if you want more details, and trust me there is much more to be had, go to the Astronomical Society of South Australia's website. Fascinating stuff.
So, Easter is all about bunnies, and eggs and cute little chicks, as we know.
The Jewish Passover holiday, on the other hand, begins on the 15th day of the month of Nisan (the first month of the ecclesiastical year, and the seventh month - eighth, in a leap year - of the civil year, on the Hebrew calendar). It lasts for 7 days, or 8 days (depending on where you live).
Passover commemorates the exodus of the Israelites from ancient Egypt (or possibly the passing over the houses of the Isrealites by the Angel of Death who was on a mission to kill all the first born males at the time). It is celebrated by obsessively cleaning out, and preferably burning, any signs of leavened (or risen) bread in the house, and replacing them with matzos. I may be missing some of the details, here, but I think that is nub of it.
Explained that way, it all makes so much sense, and renews my faith in religion.
If I put my mind to it, I could probably find a Muslim festival that occurs at around the same time and has an equally plausible genesis (if you'll pardon the pun).