I haven't read but a little of this page, but two things so far have been very interesting.

 

3 1/2 years-- Shmita Cycle of Three and a half years of Torah readings with Rabbinic commentary. (Triennial cycle Torah portion.)   Updated every week SEDERIM

 

You have to scroll down a ways to see the highlighted dates that will surprise you!  A very familiar time period!

This charts shows which years are jubilee years, according to the various opinions. D Updated 05/01/2008 YOVEL1 

 

http://www.betemunah.org/