Jazzo, I am certain you are correct in surmising that the old date for New Year's Day resulted in Aries being the first of the signs of the Zodiac. My sign is either Aries or Taurus, first or second, my birthday being Apr 20, right on the cusp. Thus my friends who are into astrology account for my often schizophrenic or contradictory beliefs and habits.
There is a wealth of religious symbolism which has grown up around the equinoxes and the solstices. The best known is that of Passover and Easter, which are, of course, related. Passover is, if I remember correctly without going to look it up, the 2nd day of the Hebrew month Nisan, and falls in our calendar somewhere around the vernal equinox. Since we know from the Gospel accounts that Easter is the Sunday following Passover (the Last Supper was probably a seder, the ritual meal celebrating Passover), it should logically be the Sunday following the Jewish celebration of Passover, and it usually is, but not always. (Incidentally, the word for Easter in a number of languages is Pasqua, or Paques, or Pasca, or some other derivation of the Hebrew "Pesach" = Passover). For some reason I have forgotten, Easter is defined in Church calendars as the Sunday following the full moon which follows the vernal equinox. Hence the possible range of dates is Mar. 25 to Apr 25 and sometimes it's a week or more away from Passover, but it's always linked to Passover.
Then there is the curious case of the feasts of the two Saints John. The feast of St. John the Evangelist is Dec. 27, which, in the days of the Julian calendar, was the winter solstice. The feast of St. John the Baptist is June 24, which used to be the summer solstice (sorry Max, you only get a brief S. Hemisph. acknowledgement). I'm positive this is some kind of symbol involving either light or renewal, or both, but needs a good deal of thought. Any ideas?
Then there is the feast of St. Michael the Archangel, which occurs on Sept. 29, or near the autumnal equinox, which celebrates the triumph of that archangel over Lucifer (= lightbearer !!) and his fellow fallen angels. This is today a minor deal even in ecclesiastical circles, but it was formerly a major holiday -- so much so that it gave its name to a season. There is a Michaelmas (= Michael mass, feast of Michael, on the same pattern as Christ-mass) quarter for financial purposes and a Michaelmas term at Oxford & Cambridge.
