Wake at the same time, including weekends
Regularity predicts outcomes better than duration does in several large studies.
Do this
Pick a wake time you can hold seven days a week and anchor to it. Let bedtime drift to meet it. If you are short on sleep, go to bed earlier rather than waking later. Get bright light within an hour of waking.
Why it works
The circadian system is entrained mainly by light at a consistent time. Shifting your wake time on weekends produces something close to jet lag every Monday. In a study of over 60,000 people, sleep regularity was a stronger predictor of mortality than sleep duration.
Where it fails
Shift workers and new parents cannot do this, and telling them to is useless. It also does not fix insomnia by itself - that needs a proper protocol, usually CBT-I.
How you’ll know
After two to three weeks you should start waking shortly before the alarm. That is the circadian system taking over.