We analyse retrospective time judging from a survey of more than fifty thousand reviews. Subjects were told to verbally estimate the time they had been waiting in the lounge until they entered the consulting room. The estimations ranged from 0 to 300 minutes. Our aim is to test whether subjects use round numbers when estimating time. We find that the round number is 5, although for longer intervals of time, the round number increases to 15, 30 and 60 minutes.