как на английском будет  1 час,1-30,12-00,20th,10-45,5-15,и 12st

1 час - It's one o'clock1-30 - It's half past one12-00 It's twelve o'clock20th twentieth10-45 - quarter to eleven5-15 quarter past five12st - может 21st? - twenty first?12th - twelfth