How the arithmetic works
Three numbers do all the work.
- Available turnaround is simply the gap between the end of one shift and the start of the next.
- Allocated time is your commute home, wind-down, sleep, getting ready and commute back.
- Unallocated buffer is what is left. It is the honest number, because it is the one that goes negative.
When the buffer is positive, the planner splits it either side of the sleep block, since that is where it goes in practice: eating and decompressing after you get in, and again after waking before you start moving. When it is negative, the planner says so instead of quietly shortening your sleep, and shows how much time there actually is.
This tool calculates the schedule from the times you provide. It does not determine how much sleep you personally need. That varies between people, and it is not something a web page can work out for you.
Protecting the block once you have planned it
Planning the sleep is the easy half. The guidance below is from CDC and NIOSH material written for nurses on shift work, and it is the same advice we cite in the sleep schedule guide.
- Sleep as soon as you get home. NIOSH suggests sleeping as soon as you get in, for example at 8am, and sleeping as long as you can, rather than staying up first. Source.
- Make the room properly dark. NIOSH advises a sleep environment dark enough that you cannot see your hand in front of your eyes, or an eye mask, with blackout shades or drapes, because daylight triggers waking. Source.
- Get light early in the shift. Alertness improves with more light exposure during the first half of the shift, which just means spending time in a brightly lit area. Source.
- A nap before nights is a recognised strategy. NIOSH cites research where a 1.5-hour nap from 3:30pm to 5:00pm left nurses reporting more alertness in the last half of a first night shift. Source.
None of that is medical advice, and if persistent sleepiness is affecting your work or driving despite enough time in bed, that is a conversation with a doctor rather than a scheduling problem.
Frequently asked
How is this different from the shift wake-up calculator?
The wake-up calculator answers one question: what time do I need to get up for a shift. This planner covers the whole period between two night shifts, so it also places the journey home, the wind-down, the sleep and the slack.
What if my sleep target does not fit?
It tells you, and shows what would fit instead. Silently compressing the sleep block would make the tool useless for exactly the turnarounds worth checking.
Does it handle split sleep?
Yes. Turn on the split option and your target is divided into a longer block after you get home and a shorter one nearer the shift, with the awake window between them on the timeline.
Is anything I type sent anywhere?
No. It all runs in your browser. We record an anonymous event that the planner was used, never a time or value you entered. Our Privacy Policy covers this.
I work nursing nights. Is there anything more specific?
Yes. The night shift nurse sleep schedule guide works through 7pm to 7am and 6pm to 6am rotas, a run of three nights, the first night and the day after the last, and it links each example back into this planner with the times already filled in. For the app rather than the schedule, Mornio for nurses covers the earlies, the nights and the nap before one.