9pm is 2100 hours Navy / Military time, which is based on a 24 hour clock system. 12am is 0000 hours, 1am is 0100, 12pm is 1200, 6pm is 1800 hours, etc.
3 oclock
12 oclock 6 oclock
In the evening when the sun is just about to set and you are relaxed and have a good book to read!
nine oclock and six oclock
2.00 oclock
12 oclock
9 oclock
at 9 oclock
It would be 8 Oclock Minus one hour.
at 11 oclock
6 oclock 7 ocklock or 8 oclock i am very not sure
10 oclock monday thru Friday 8 oclock on Saturday appointments only on Sunday