My contract specifies my working hours are 9-5 and I have 30 mins unpaid for lunch. I have noticed that everyone, regardless of what time they start having lunch or what their contracted start and finish time is, is always back to work by 1 pm. When I questioned this with a colleague I was told lunch break is 12:30 until 1 and if you can't take it then, then tough. For example if you have a meeting that overruns until 12:40, you still have to be back at your desk for 1.
I like going for a walk and occasionally I've left at 12:45 and come back for 13:15. AIBU to think this is fine and to say nuts to the 12:30 until 13:00 "rule"?