Offer the hours you are already awake in, and say the finish time in the same message. NIOSH's night-shift module tells nurses to sleep on getting home, for example at 8 a.m., and on days off to stay up until 3 or 4 a.m. and sleep until noon or 1 p.m., so that 8 a.m. to noon stays sleep time in every 24-hour period. That leaves roughly 2 p.m. to 10 p.m. as the block to offer on a day off. The condition that changes it is the shift that follows: on a night you work, the block ends at the hour you need to start getting ready.
The anchor hours come first, then the invitation
Keeping the same hours as sleep on work days and rest days is the point of that NIOSH advice, and it is what makes an offer repeatable. A plan that pushes you to 2 a.m. on a Tuesday costs the Wednesday shift, not just the Tuesday.
Build the map once, in writing, rather than recalculating it for every invitation. Then it is a lookup, and the answer arrives in one message instead of three.
Scroll sideways to see the full table →
| The day | Hours to offer | What to keep out | Hard finish |
|---|---|---|---|
| Day off, no shift either side | 2 p.m. to 10 p.m. | Anything before noon | Last departure home |
| Night you work | 2 p.m. to 4:30 p.m. | Meals that run long | 3 hours before clock-in |
| Morning after a shift | None before 2 p.m. | Brunch, errands, appointments | Sleep window is booked |
The middle row is the one people get wrong. A coffee at 3 p.m. before a 7 p.m. start works; a 5 p.m. dinner does not.
Last departure sets the end of the night
Pick the end time from the transit timetable, not from the mood of the table. BART publishes its service hours as weekdays 5:00 a.m. to midnight, Saturday 6:00 a.m. to midnight and Sunday 8:00 a.m. to midnight, so a Sunday plan that starts at 8 p.m. has four hours in it, and the Sunday morning trip that would get you there does not exist before 8 a.m.
Read your own agency's page the same way and write the number down: the last departure, and the walk to the station. A backup route for the trip home is worth settling before the evening, not at 11:40 p.m.
The drive home is part of the invitation
If the plan ends in a drive, the timing matters as much as the hour. NIOSH's driving module puts most fatigue-related crashes between 4 and 6 a.m., with further clusters from midnight to 2 a.m. and from 2 to 4 p.m., reports that people sleeping 6 to 7 hours a night are twice as likely to be in a sleep-related crash as those sleeping 8 or more, and cites the American Nurses Association's 2011 Health and Safety Survey finding that 1 in 10 nurses reported a car accident they believed was related to shift-work fatigue.
Two clusters there are social hours, not work hours. An evening that ends with a 1 a.m. drive lands inside one of them, so settle the trip from the venue the way you settle the trip from work: a ride, a later start, or a plan that ends before midnight.
One worked example: Friday off, dinner in the city
Example, with published times. You are off Friday and free from 2 p.m. Dinner is at 6:30 p.m., the station is a 12-minute walk from the restaurant, and BART's weekday service runs to midnight. You set the finish at 10:30 p.m., which leaves 90 minutes of slack for a late table or a slow check, and you are home before the midnight-to-2 a.m. crash window opens.
Written as one message: "Free Friday from 2 p.m. Dinner at 6:30 works, I have to leave by 10:30 for the last train."
The three messages to keep on hand
Give people the map once. NIOSH's coping module suggests marking your work hours and likely sleep times on the home calendar or on cards you hand out, so the invitations start in the right window without an explanation each time.
The offer: "I'm off Thursday and free 2 to 10 p.m. Dinner at 6?" The counter-offer, when the hour is wrong: "I work Thursday night, so 6 p.m. doesn't work. I can do coffee at 3 p.m., or Saturday from 2." The no with a date attached: "That morning is my sleep window. Sunday afternoon from 2 p.m. is open." Every one of them names an hour, and a no that names a date keeps the plan alive.