Since we're all being exacting here… =p

> (first day of spring)

It's actually the March equinox. "Spring" is true only in the northern hemisphere. What's more it's the ecclesiastical equinox, not the astronomical equinox, whose date actually varies depending on the year.

Never mind that all this is descriptive of dating in countries that grew up with Western Christianity. Countries where Eastern traditions dominate often date it differently.

All good will to you both = )

I still find it easier to explain it as "14 Nisan *energetic hand wave*!!" :).