Video Library · Calculator · Place Finder · Periodic Table · Perpetual Calendar · Homework Help · Spelling Checker · Distance Calculator · Conversion Tool. Why do we still celebrate Old Testament holidays such as Passover, since Jesus has . Join our mailing list today and stay up to date with all the latest news! Passover dates A.D.. The following astronomical data in the first three columns below was obtained from the U.S. Naval Observatory Astronomical.