Q: WHAT YEAR DID OMRI BEGIN HIS REIGN IN ISRAEL?
A: IT DEPENDS WHAT CALENDAR YOU ARE USING!
On the Gregorian calendar (the one you might have on your wall) the year was 869 BC.
On the Hebrew calendar, sometimes called the biblical calendar, the year was 3178 AM.
I Kings 16:23 – In the thirty and first year of Asa king of Judah began Omri to reign over Israel, twelve years: six years reigned he in Tirzah.