But it varies continuously on scales much smaller than seasonal changes. And seasonal changes are what affect day/night times. Without discrete jumps, you can a

But it varies continuously on scales much smaller than seasonal changes. And seasonal changes are what affect day/night times. Without discrete jumps, you can actually consider a solar-noon to solar-noon time cycle as a day, and see that day + night must add up to a constant for any given cycle, therefore more night means less day.