'Weeks' in the Bible

Let seven weeks be numbered from the first day when the grain is cut.

Then keep the feast of weeks to the Lord your God, with an offering freely given to him from the wealth he has given you:

Three times in the year let all your males come before the Lord your God in the place named by him; at the feast of unleavened bread, the feast of weeks, and the feast of tents: and they are not to come before the Lord with nothing in their hands;