"Начало в три часа ночи."

Translation: The beginning is at three o'clock in the morning.

[peachtree2]

Sorry, I'm having doubts here. ночи here is genitive or prepositional?

[ericwillfixit]

'The beginning is at three in the morning' was rejected.
In other sentences leaving out 'o'clock' is accepted.
Could you at least be consistent in what you accept and reject? Thank You!

[JanisaChatte]

Sorry for the inconsistency! It's accepted now :)