AccountRight Time Sheets - how to enter a 1/2 hour worked

Hi

We're new to timesheets and can not find the answer to what I think is probably a silly question but none the less we have the question.

If we have an employee working for a half hour how does that get inputted into the time sheet? for example the employee worked 4 and a half hours, is it imputed as 4.5 (f4 hours and a half) or 4.3 (4 hours and 30 minutes)

We run accountright plus

Thanks