I don't understand what you mean by this but I will assume you mean how many hours are needed to get to 24 hours from 5:30pm. In that case the answer would be 6 hours and 30 minutes since 5:30 would be 17 1/2 hours from 12:00am which would signify the start of a new day even if nobody is awake at that time.
Actually you could also mean turn 5:30 into 17:30 which I think would be called military time. I'm not sure.