Twenty-four hours on duty, then forty-eight off, repeating on a three-day cycle. Every third day you are back at shift change. The cycle is short enough that the same wake anchor can carry all three days, and it lands the two days off in a fixed order every time: the day you come off the truck, then a clear day before you go back.
These are example times, not your times. Everything below is computed from a single pair of wake anchors: 6:30 AM on a work day and 7:30 AM on a rest day. A 6:30 AM wake puts you at an 0830 shift change with time to get to the station, and a 7:30 AM rest-day anchor keeps the reset day within an hour of the shift day. If your anchors are different, every window below shifts with them, which is what the plan builder does with your own numbers.
The plan works backward from the wake anchor rather than forward from bedtime, because bedtime is the part your schedule takes away from you. The sleep target on each day is the anchor minus the sleep opportunity; the caffeine cutoff is eight hours before that target; the last real meal is three hours before wind-down starts. So the anchor is the only number you set, and the rest falls out of it.
The 24 you are on duty. 24 hours on duty, going on the tour at 8:30 AM.
| Wake anchor | 6:30 AM |
|---|---|
| Bright light | 6:30 AM to 8:00 AM |
| Caffeine | 7:30 AM to 8:00 AM (first cup), stop by 2:30 PM |
| Planned nap | 10:30 AM to 12:00 PM |
| Last real meal | by 6:00 PM |
| Wind-down | 9:00 PM to 9:30 PM |
| Sleep target | 10:30 PM |
The day you come off the 24.
| Wake anchor | 6:30 AM |
|---|---|
| Bright light | 6:30 AM to 8:00 AM |
| Caffeine | 7:30 AM to 8:00 AM (first cup), stop by 4:30 PM |
| Planned nap | 10:30 AM to 12:00 PM |
| Last real meal | by 8:00 PM |
| Wind-down | 11:00 PM to 11:30 PM |
| Sleep target | 12:30 AM |
The second day off, before you go back.
| Wake anchor | 7:30 AM |
|---|---|
| Bright light | 7:30 AM to 9:00 AM |
| Caffeine | 8:30 AM to 9:00 AM (first cup), stop by 3:30 PM |
| Last real meal | by 7:00 PM |
| Wind-down | 10:00 PM to 10:30 PM |
| Sleep target | 11:30 PM |
The sleep you get on duty is not schedulable, so the plan has to be built around the two days off, and the structure makes those two days do different jobs. The first is short — you are awake from shift change and the night is already close — so the engine gives it a shorter sleep opportunity aligned to the shift-day anchor rather than a full eight. Chase eight hours in the morning after a 24 and you take them out of that night. The second day off is the only place in the whole cycle where a full night has room, and it is the last thing before the next 24. Rested going into a shift is decided there.
The day you come off the truck is a recovery day: a shorter sleep aligned to your shift-day anchor, one deliberate nap, and an early night. Do not chase eight hours in the morning - it steals the night. The second day is the reset day: this is where the rest-day anchor lives, and where a full night has room. Going into the next 24 rested is decided on that second day, not the first.
Eight hours before the sleep opportunity you are protecting. In the worked example on this page, a 6:30 AM wake anchor on a work day puts the sleep target at 10:30 PM, so the last caffeine of any kind lands at 2:30 PM. Move the anchor and the cutoff moves with it — the eight hours is the rule, not the clock time.
The plan sets the sleep target backward from the wake anchor rather than forward from the end of a shift. In the example here, a 6:30 AM work-day anchor gives a 10:30 PM sleep target, with wind-down starting at 9:00 PM. On a rest day the 7:30 AM anchor gives an 11:30 PM target.
Within 90 minutes of waking, whatever the sun is doing. In the worked example that is 6:30 AM to 8:00 AM on a work day. Ten to fifteen minutes is enough. Then keep bright light off you in the three hours before the sleep target.
One nap, taken on purpose, four to five and a half hours after waking — 10:30 AM to 12:00 PM in the worked example on this page. Twenty to thirty minutes, or a full ninety. Anything in between leaves you groggy.
Recovery day (off at shift change) is planned as its own kind of day rather than a normal one. In the example, it runs on a shorter sleep opportunity ending at 6:30 AM, with the caffeine cutoff at 4:30 PM and the last real meal by 8:00 PM.
The plan builder takes six questions — your pattern, your two wake times, your last cup of coffee — and computes the same windows against the schedule you actually work, as a visual timeline for each kind of day. Free, printable, no account.
Build my free sleep planEvery window on this page comes from one of a handful of rules, and the Shift Worker's Field Manual is where those rules are laid out with their sources: why the wake anchor is the lever rather than bedtime, what light does to the body clock and when, the eight-hour caffeine cutoff and where it comes from, and what to do when the problem is bigger than a schedule.
Free, no account
One short email a week: what the research actually says, and what to do with it on your schedule.
One email a week. Unsubscribe anytime.