This clock shows 3:15. After how long will its mirror image first show 3:15?

The image shows 3:15 when the clock itself shows 11:60 - 3:15 = 8:45. From 3:15 to 8:45 is 5 hours 30 minutes. (8 h 45 min confuses the time of day with the waiting time; 4 h 30 min and 6 h 30 min are counting slips.)