This game is played across the world, and not every country observes Daylight Saving Time. Heck, there are certain states, or portions of states, in the United States that don't observe DST.
On top of that, if you knew your Elder Scrolls lore, you would know the great Argonian, Flies-Kite-In-Storm, who first postulated the idea of Daylight Saving Time, was not credited with this feat until sometime in the Fourth Era, between 4E 120 and 4E 123.