Here is a fascinating Shiur (in Hebrew) by Rav Ezra Sheinberg around the Pasuk of Megillat Ruth that I have
written about. The Rav explains the book
Tzaddik Yesod Olam, the Arizal's commentary on Megillat Ruth. Among other things, he explains the date of the begining of the Geula. It is a date that you know.