LeBron James -- My Big, Fat YOM KIPPUR Wedding!

LeBron James has finally selected a WEDDING DATE ... which is great news ... for everyone except LeBron's Jewish friends ... 'cause it's all going down on Yom Kippur ... TMZ has learned.

We've obtained a copy of King James' "Save The Date" ... which instructs his friends to block out Friday Sept. 13 through Sunday Sept. 15 for the NBA star's destination wedding to fiancee Savannah Brinson in exotic San Diego, CA.

The "Save the Date" even came with a fun caricature of Bron, Savannah and their 2 children ... each dressed in their finest wedding outfits. Cute.

But here's the problem ... Sept. 13 is the beginning of Yom Kippur -- a high holy day in the Jewish religion in which Hebrews and Shebrews are supposed to fast for roughly 24 hours while praying their faces off in temple.

And for the record, James DOES have Jewish friends ... including the famous Rabbi Yishayahu Yosef Pinto (pictured below) ... a man known around New York as the "Rabbi to the Business Stars."

The good news ... LeBron will probably save a bunch of cash on the buffet.
The bad news ... he won't be able to brag about the savings to the people who would appreciate it.

Mazel Tov!!!