Jennifer Lopez is set to perform at a Ukrainian wedding in 3 hours ... but here's the problem -- she doesn't hit the stage until 11:30, and you know how the Ukrainians like their vodka.
Jennifer is reportedly pocketing a million bucks for her performance. Our wedding spies tell us there are roughly 300 people attending the bash.
A source connected to Jennifer calls the performance time "a little weird," but hey, drunk or not, a million bucks is a million bucks.
Fun fact ... the World Health Organization has rated the Ukraine as #1 in the world for alcohol consumption among youth.
BTW, the money Jennifer makes is hers and hers alone, since she's already separated from Marc Anthony.