Why is Shavuot celebrated today [Wednesday] instead of on the "day after the sabbath" as the Torah says (Lev. 23:15,16)?
Passover is a movable holiday, but according to Leviticus 23, both the Feast of First Fruits [Lev. 23:10,11] and Shavuot move with it. The Feast of First Fruits (Wave of Sheaf Offering) takes place on the first 'morrow after the Sabbath' after the Passover. And then, from that very day, seven Sabbaths are counted and "even unto the morrow after the seventh Sabbath shall ye number fifty days." That is when Shavuot is to be celebrated. And we all know that the 'morrow after the Sabbath' is always a Sunday.
So, why isn't Shavuot celebrated on a Sunday?