When exactly, is the Omer brought?
Rashi (citing Menachos, 66a): On the second day of Pesach.
Rashi: The Torah calls the the first day of Pesach 'Shabbos'. It cannot mean literally Shabbos, because if it did, how would we know which one? - See Ramban, who elaborates. Refer also to 23:15:1:2.
QUESTIONS ON RASHI
Rashi writes that "Macharas ha'Shabbos" is the 16th. "Macharas ha'Pesach" (Bamidbar 33:3) is the day we left Egypt, i.e. the 15th!
The 14th is called Pesach, i.e. the day of Shechitas Pesach, but it is not called Shabbos.
Moshav Zekenim left this difficult.