Sleep schedule calculator

A full week of bedtimes and alarms, derived from your sleep need and a fixed wake time — the wake time is the anchor; the bedtime is arithmetic. Switch to shift work and it builds the anchor-sleep schedule for early, evening or night rotations, with the days-off rule that actually makes shift sleep work: hold the window, don't flip it.

Schedule type
years

Target: 8 h per night.

min

Capped at 60 min — more drifts your clock.

Weekly sleep schedule
DayIn bedWakeAsleepNote
Mon10:15 pm6:30 am8 hIn bed 10:15 pm, 8 h 15 min before a 6:30 am alarm.
Tue10:15 pm6:30 am8 hIn bed 10:15 pm, 8 h 15 min before a 6:30 am alarm.
Wed10:15 pm6:30 am8 hIn bed 10:15 pm, 8 h 15 min before a 6:30 am alarm.
Thu10:15 pm6:30 am8 hIn bed 10:15 pm, 8 h 15 min before a 6:30 am alarm.
Fri10:15 pm6:30 am8 hIn bed 10:15 pm, 8 h 15 min before a 6:30 am alarm.
Satoff10:45 pm7:00 am8 hLie-in capped at 30 min — more than that drifts your clock and makes Sun harder.
Sunoff10:45 pm7:00 am8 hLie-in capped at 30 min — more than that drifts your clock and makes Mon harder.

Planning tool, not medical advice. These figures are population averages for scheduling your sleep — they don't diagnose or treat any condition. See a clinician for persistent sleep problems.

Why is the wake time the anchor?

Your clock entrains to regularity, and the most regular signal you control is the alarm. Fix it within ~30 minutes every day — weekends included — and the bedtime stops being a nightly negotiation and becomes a derived value: wake time minus sleep need minus time to fall asleep. The circadian rhythm calculator then layers the light schedule on top of that anchor.

Why are weekends the problem?

Sleeping in two hours on Saturday feels like repayment and acts like a flight: you have shifted your clock two zones west, and Monday's alarm now lands in your biological early morning — the mechanism behind "social jet lag", which tracks with worse mood and metabolic markers in the research. The calculator lets you budget a lie-in but caps it at 60 minutes, because that is roughly where the repayment stops paying and the drift starts costing.

How does anchor sleep work for shift workers?

The single biggest mistake in shift-work sleep is the full flip — living nights on work days and days on days off, re-adapting from zero every week. The studied alternative is anchor sleep: one stable window held across the whole week (with a small, capped drift on days off), so the adaptation you build survives the weekend. For night shifts that window sits after the shift ends; pair it with complete blackout, the wind-down planner, and — for the first commute home — sunglasses, because morning light on the drive home is telling your clock exactly the wrong thing.