Wake Up at the Same Time

The body keeps time using a circadian rhythm, a roughly twenty-four-hour cycle that governs hormone release, body temperature, alertness, and sleep onset. The single most powerful signal for setting that rhythm is light, particularly the light you receive in the first hour after waking.

This is why wake time is more important than bedtime. Going to bed an hour later than usual on a Friday is forgivable. Sleeping in three hours later on Saturday morning is not, it shifts your rhythm forward and produces the well-known phenomenon of social jet lag, which is why so many people feel awful Sunday night and Monday morning.

Anchor your wake time within thirty minutes seven days a week. Within ten to fourteen days, your body adjusts. Falling asleep gets easier. Waking gets easier. The weekend lie-in feels great in the moment and costs you a full week of feeling slightly off. The math rarely works in its favor.