Enter the shift start and end times along with the time you use after the shift and after waking, and the tool reports how many hours and minutes of the off-duty gap are left for sleep, then back-calculates the bedtime and wake time for placing your chosen sleep length either right after the shift or right before the next one. Shifts that pass midnight are labeled with the day they land on, so a rotation plan no longer needs to be worked out by hand.
Every span is kept as whole minutes and shown as hours and minutes, so a minute figure of 60 never appears, and the bedtime and wake time carry a label for how many days after the shift start day they fall. The off-duty gap is worked out on the assumption that the same shift repeats every 24 hours. Written as of October 2026, and the sleep length and preparation times all come from your own input.
No recommended sleep length and no claim about health effects of sleep are offered. There is no single official standard for how many hours suit a shift worker, and that judgment belongs to medicine. Sleep quality and accumulated fatigue are not assessed either, and the output is plain clock arithmetic, so speak with a clinician if you are worried about how you feel.
Frequently Asked Questions
No. The sleep length is a field you fill in yourself, and the tool only works out whether that length fits inside the off-duty gap and what the bedtime and wake time become if it does.
For sleep placed right after the shift, preparation time is added to the shift end to give the bedtime, then the sleep length is added to give the wake time. For sleep placed before the next shift, preparation time is subtracted from the next start to give the wake time, then the sleep length is subtracted to give the bedtime.
The calculation assumes the same shift repeats every 24 hours. For days where the rotation changes or a day off follows a run of nights, enter that day own shift times and work each one out separately.