Below is link to video series proving weeks do not continually cycle in the exodus account. It also shows that Shavuot is a time period of 7 sabbaths + 50 days. This is also confirmed in the exodus. Excellent. https://m.youtube.com/playlist?list=PLABB88BB8D101010D https://m.youtube.com/playlist?list=PL4E7C2C70292D332F The second link has lunar solar sabbath part 1,2,3. Watch from the playlist. Also the video titled “Jews and the sabbath” is good.