Talking Parsha - Emor: Is it after Shabbat or after Pesach?

The Torah speaks about Shavuot as 'after the Shabbat.' Is Shavuot 7 weeks long? Why is it defined by being 'after Shabbat?'

Arutz Sheva Staff ,

Talking Parsha
Talking Parsha
Tuvia and Yitzi

Our parsha (Torah portion) devotes individual paragraphs for each chag (holiday), but when it comes to Shavuot (the Festival of Weeks), instead of focusing on the one-day chag on the 6th day of the Hebrew month of Sivan, the Torah describes a chag that starts, "after the Shabbat," (after the first day of Pesach (Passover)) and continues and develops for 49 days.

Is Shavuot actually a 7-week -long chag? Why is it defined by being "after the Shabbat," and not by its date?