I'm a lunchtime supervisor. I'm contracted to work 11.30-1.30. I always blow the whistle to signal that it's time to come in at 1.25 its often 5-10min after that that I actually leave the building. Everyone does the same and never complains. Last week I blew the whistle at 1.20 to allow extra time that was needed to round up the reception class, obviously they aren't used to the routine or us and they keep running off etc. I get an email today complaining that the whistle is being blown to early. Obviously by blowing early the rest of the school re-enters school 5 min earlier than normal. I will mention it tomorrow but I feel this should of been obvious. Am I expected to stay even longer after my time has finished which we already do? How are we expected to blow the whistle at 1.30, line the children up and walk them in and finish at 1.30? AIBU?