Taking this additional, my look at is "at" should be employed for gatherings that are not days in the 7 days (at Xmas, at Easter, in the weekend, at lunchtime, at nine o'clock) irrelevant of size, and "on" exactly where the time is each day of your 7 days (on Saturday). I'd argue this is to try and do with The point that "at" indicates a certain ov