Ah yes, but "day" is not meant to be the period between one midnight and the next. With daylight saving there would be one 23 hour day and one 25 hour day in a year with all the others being 24 hours, as SharonA said.

"Day" here is meant to be between sunrise and sunset, and the clocks are always put back or forward in the middle of the night. So there could be one night that is one hour shorter (by the clock) and one that is an hour longer.

But I'm sure you already knew that DMcG ;-)