12:00 - twelve o'clock, 14:00 two o'clock, 17:00 - five o'clock, 23:00 eleven o'clock, 18:15 - quarter past six, 15:15 - quarter past three, 20:15 - quarter past eight, 19:30 - half past seven, 19:45 - quarter to eight , 18:15 - quarter past six, 21:35 - twenty five minutes to ten