The date of Shavu’ot
No explicit date is given in the Torah for Shavu’ot. We know it has to come seven weeks after Pesach.
In Second Temple times it was hotly debated between the Pharisees, who said that in the command to count seven weeks “from the morrow of the Sabbath”, “Sabbath” means the first festival day of Pesach – and the Sadducees, who said that “Sabbath” means Saturday. The Pharisee view prevailed, so the two festivals are intrinsically linked.
The outcome is that the physical freedom of Pesach, when the people became an independent nation, is complemented by the moral freedom of Shavu’ot, when they decided that they would accept the Torah as their national constitution.