Build an anchor-sleep or split-sleep schedule for day, swing, night and 12-hour rotating shifts. Enter your shift times and commute to get your sleep blocks, sunlight and sunglasses windows, melatonin timing and caffeine cutoff. Everything is calculated privately in your browser.

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What Is Anchor Sleep?

Anchor sleep is a block of about 4 hours taken at the same clock time every day, including days off. Research on shift workers suggests that a fixed anchor keeps part of the body clock steady, so it adapts more easily to a changing schedule. The rest of your sleep is added around it as a recharge block or nap.

Split Sleep for Night and Rotating Shifts

Many night workers cannot get one long sleep before a 12-hour shift. A split plan solves this: a 4-hour morning anchor block after the shift, then a 2.5-hour recharge block before the next shift. That gives 6.5 hours of core sleep, and you can top it up with a longer sleep on days off. This is better than staying awake all day and trying to catch up later.

Sunlight, Sunglasses and Circadian Timing

Light is the strongest signal for your body clock. Bright light early in a night shift tells your brain to stay alert. Morning sunlight on the drive home tells it that the day has begun and delays sleep, so wear dark or amber sunglasses from about 30 minutes before the shift ends until you are in a dark bedroom. Before the next shift, get 30 minutes of bright light after waking.

Melatonin Surge Windows

Your body releases melatonin in dim light roughly 2 hours before your usual sleep time. Dim your lights and screens during this window to let that surge happen. Some people take a low dose of 0.5 to 3 mg about 30 to 60 minutes before the main sleep block, but supplements are not suitable for everyone, so check with a doctor or pharmacist first. Stop caffeine about 6 hours before sleep.

Step-by-Step Examples

Graveyard Shift: 11:00 PM to 7:00 AM, 30-Minute Commute

Choose Graveyard / Night. The planner gives a morning anchor block from 8:00 AM to 12:00 PM and a recharge block from 7:00 PM to 9:30 PM, for 6.5 hours of core sleep. Wear sunglasses from 6:30 AM until 8:00 AM, dim your lights from 6:00 AM, and stop caffeine by 2:00 AM.

Swing Shift: 3:00 PM to 11:00 PM, 30-Minute Commute

Choose Swing. You sleep from 12:30 AM to 8:30 AM for a full 8 hours, with an optional 20-minute nap at 11:30 AM. Get sunlight from 8:30 AM, dim your lights from 10:30 PM and stop caffeine by 6:30 PM.

12-Hour Rotating Night: 7:00 PM to 7:00 AM, 45-Minute Commute

Choose 12-Hour Rotating and set a 45-minute commute. The planner gives an anchor block from 8:15 AM to 12:15 PM and a recharge block from 2:45 PM to 5:15 PM. Rotate forward, from days to nights, and take at least two full days off after a run of nights.

Shift Timing vs Primary and Anchor Sleep Blocks

All standard 8-hour and 12-hour shifts, listed by start time, assuming a 30-minute commute each way. Night shifts use the split anchor plan, and day and swing shifts use one consolidated block.

Photobiological Light Exposure and Blue-Blocker Protocol

Exact sunglasses windows by shift end time, assuming sunrise near 6:00 AM and a 30-minute commute. If your commute is longer, extend the window by the extra minutes, and shift the times with your local sunrise.

Circadian Adaptation Matrix for Rapidly Rotating Shifts

Forward, or clockwise, rotation moves your shift later and matches the natural tendency of the body clock to run slightly longer than 24 hours. It generally causes less digestive and cardiovascular strain than backward rotation.

Frequently Asked Questions

Medical disclaimer: This planner is an educational tool and not medical advice. Shift work is linked to sleep disorders, digestive problems and cardiovascular strain. If you struggle to sleep or stay awake despite a good schedule, speak to a doctor about shift work sleep disorder. Never drive or operate machinery when drowsy.