"half past five" is not accepted. In a previous question, 24h clock was not allowed, but here it seems to be mandated. Perhaps some validation of the entry fields would make this less frustrating. Keep up the good work!
Five thirty hours was not accepted, five thirty pm was given as the correct answer. Why pm and not hours, which also indicates time? And why pm and not am? In the 24 hour clock surely am would be most correct?