Today, it usage has broadend. 1.it is used primarily to express frustration for the the unwelcomed arrival of someone and 2. A shortend 'command' if you will, ordering the subject to go to the cinema with the subject at that time. It's usage is favuored especially when the subject has an important event, a 'test' for example, the following day, in order to deprive them from sleep and revision. The commanded version of '11 o'clock' is surprisingly used at 11 o'clock GMT.
Joe Thompson: Hi, is Ashweh there?
David Siboo: WHAT THE FUCKING FUCK?!! ITS 11 O'CLOCK!!!!
Joe Thompson: But it's not even 10 o'clo..
David Siboo: SHUT THE FUCK UP YOU FUCKING FAG.
2. Susan Siboo: Ashweh, 11 o'clock.
Ashweh: Ok, dont worry, i dont need much sleep today, ive only got a test tommorow