It's six o'clock already.

Source: Tatoeba

I'll be back at seven o'clock.

Source: Tatoeba

The game ended at nine o'clock.

Source: Tatoeba

This braised pork is still too watery. Cook it for another ten minutes to thicken the sauce, so the flavor sticks to the meat.

Source: Tatoeba

I have been writing since two o'clock without a break.

Source: Tatoeba