Daylight saving time begins at 2 a.m. this Sunday, meaning it's once again time to move the clocks ahead one hour. The change, which costs millions of Americans an hour of sleep, effectively moves an hour of daylight from the morning to the evening.

Generally, adjusting to the time change in the spring is more difficult than when the clocks go back one hour in the fall. But losing an hour of sleep may do more than just make you feel groggy.