If the equinox is on a Sunday and mother's day on the 20th then the clocks go forward during mother's day and they only get 23 hours. I do don't know how often that happens, I'm not rain man. It does happen sometimes though. They didn't think it through. They should make mother's day on Saturday.
It is also the last third of the month. Tomorrow is the start of the third Alan-week. My own unique way of looking at the passing of time.