Briefly, it may be explained here that Easter day is the first Sunday after the full moon following the vernal equinox.
An instance is given, in L' Art de verifier les dates, of a date in which the year is reckoned from the 18th of March; but it is probable that this refers to the astronomical year, and that the 18th of March was taken for the day of the vernal equinox.
At Tyre the year was counted from the 19th of our October, at Gaza from the 28th of the same month, and at Damascus from the vernal equinox.
Positive proof of the high antiquity of the Hindu lunar zodiac is nevertheless afforded by the undoubted fact that the primitive series opened with Krittika (the Pleiades) as the sign of the vernal equinox.
The modern nakshatras are twenty-seven equal ecliptical divisions, the origin of which shifts, like that of the solar signs, with the vernal equinox.