How to Reset Your Circadian Clock

Late nights, jet lag or shift work can leave your body clock badly out of step with the day. The good news is that the clock is resettable — with the right cues, in the right order, over a few days.

Step 1: Fix your wake time

Pick a realistic wake time and hold it every day, including weekends. A steady wake time is the anchor for everything else in your circadian rhythm. Resist the urge to "catch up" with long lie-ins, which just push the clock later again.

Step 2: Front-load light, dim the evening

Get bright morning light within an hour of waking.
Dim indoor lights and screens in the last hour or two before bed.
If it is dark outside in the morning, consider a light box.

Step 3: Use meals, movement and patience

Eat earlier and avoid heavy late meals; morning movement reinforces the "daytime" signal. Shift bedtime gradually — 15–30 minutes earlier each night rather than all at once. For jet lag specifically, adjust toward the destination's schedule before you travel. Most clocks reset within several days; if yours will not budge, or you do shift work, see the NHS sleep and tiredness guidance and the Sleep Foundation.