7pm to 7am is the most common night shift in healthcare and industry. It is also the one most likely to drop your worst hour right on top of your drive home. Here is what the schedule should look like, and why.
WHAT THIS PAGE WILL NOT TELL YOU
This page explains how the timing works and why. It does not print your six times, because they are not printable: they move with your finish time, your commute and the hour you wake with no alarm. Four questions, about forty seconds, no account.
- Your crash window
- Bright light: start and stop
- Sunglasses on: start and stop
- Main sleep: in bed and up
- Pre-shift nap: and when to set the alarm
- Last caffeine
FREE TO SEE YOUR CRASH WINDOW · NO ACCOUNT · 40 SECONDS
Where your crash window lands on a 7pm–7am shift
Your worst hour sits about two hours before the time you would wake up on your own with no alarm. That single fact is the whole calculation, and it is why an early riser and a late one working the same shift are in different trouble at different times. On a 7pm to 7am roster it lands late, in the last hours of the shift and the drive home, which is why the drive feels harder than the shift did. Where it lands for you is the first thing the tool works out.
Everything below is the mechanism. The six clock times it produces depend on your finish time, your commute and how early you wake unaided, so this page cannot print them. Get yours in about forty seconds.
The sleep window that actually works
The gap between walking through the door and getting into bed is the part you control, and it should be short. Errands first is how eight hours of opportunity turns into four hours of sleep. Day sleep also runs shorter than night sleep, so the target is not one long block, it is a main block plus a nap that add up. Blackout blinds, and a phone in another room. The two clock times, when the block starts and when the nap has to end, come out of your shift and your commute rather than out of a table.
Light: the part almost everyone gets backwards
Bright light in the first half of your shift pushes your clock later. That is the direction you want. Daylight on the drive home does the opposite and undoes it. So: dark wraparound sunglasses on before you step outside, and keep them on until you are in a blacked-out room. It is the highest-value habit on this roster.
Caffeine cutoff
Caffeine has a half-life of about five hours, so half of whatever you drink to survive the last stretch is still working on you while you are trying to sleep. The cutoff is not a time of day, it is a subtraction: roughly six hours back from when you are actually asleep, which depends on when you finish and how long you drive. That is why a coffee late in the shift is the reason you are lying awake afterwards, and why the cutoff is one of the six times the tool computes rather than a number this page can print.
Common questions
+ − When should I sleep after a 7pm to 7am shift?
Get into bed within about 45 minutes of getting home, so roughly 8am after a 7am finish. Daytime sleep runs shorter and breaks up more than night sleep, so plan for six or seven hours rather than eight, and take a nap before the next shift instead of forcing the missing hour in the morning.
+ − Why do I feel worse on the drive home than during the shift?
Your lowest point sits about two hours before the time you would wake up on your own, which on this roster usually falls between 4am and 6am. That is the end of the shift and the drive, not the middle of it. Alertness and reaction time bottom out around that point.
+ − Do sunglasses on the drive home actually matter?
They are the highest value habit on this roster. Daylight after your low point pushes your clock earlier, which is the opposite of what a night worker wants, and it undoes the light you got during the shift. Dark wraparound glasses from the door of the building until you are in a blacked out room.
+ − How many hours of sleep should I expect on nights?
Less than you would get at night, and that is normal rather than a failure. Budget six to seven hours of day sleep plus a nap before the shift. Two blocks you actually get beat one eight hour block that keeps getting interrupted.
+ − What is the 3-3-3 rule for sleep?
It is not a schedule, it is a screening question. The version clinicians use asks whether poor sleep has run at least three nights a week, for at least three months, with at least three knock-on effects in the day. Online it gets muddled with wind-down countdowns like 10-3-2-1, which are a different thing. As a self-test for someone working twelve hour nights it tells you almost nothing, because the roster alone ticks all three boxes. If you think something is actually wrong, that is a question for a clinician rather than for a mnemonic. What is adjustable is where your sleep sits relative to your worst hour.
What this is based on
Every rule the plan runs on, and where each one comes fromRelated
ShiftDawn is a scheduling and education tool built on published circadian research. Not medical advice, not a diagnosis. If you suspect a sleep disorder, see a clinician.