I'm in San Francisco this weekend for my first celebration of Passover. As I've never observed a religious holiday in a purely secular setting (and, no, Christmas doesn't count), this should be fairly fun and educational. Growing up, I always thought Easter and Passover occured around roughly the same time of year, but of course this isn't strictly the case. This year Easter was really early: it falls on the first Sunday after the first full moon after the first day of Spring, which this year all happened to make Easter three days after the Vernal Equinox. And, of course, leave it to an astronomer to explain all of the intricate calendar calculations and relations between Easter, Orthodox Easter, Passover, and Rosh Hoshanah. Basically, the confusing arises when the Vernal Equinox is approximated to be (as opposed to basing these holidays on when the Vernal Equinox actually is).