This clock is always accurate.
“The Sunday that marks the return of Daylight Saving Time is a shorter day. Make it a shorter day with fewer activities, not a shorter morning with less sleep,” says David Cloud, CEO of the National Sleep Foundation. The effect of that lost hour of sleep may be felt for several days the following week. In fact, one study shows that many people will sleep an average of 40 minutes less the night after they change their clocks.
The remedy can be a simple one, Cloud says. “Give yourself a treat and sleep in that Sunday morning.” If that isn’t possible, Cloud suggests taking a short 20-30 minute nap Sunday afternoon, though not close to bed time, which can disrupt nighttime sleep. You can also try to sleep more than usual a few nights prior to and immediately following the time change.