9/80 Work Schedule: Which Friday Am I Off? Calendar & Guide
Pick the Monday that starts your long week below and get every off-Friday for the next 12 months — the one question every 9/80 worker googles before booking anything.
How the 9/80 schedule works
The 9/80 compresses the classic two-week, ten-day office schedule into nine days — same 80 hours, one extra day of life. The rhythm alternates between a long week and a short week:
| Week | Mon–Thu | Friday |
|---|---|---|
| Long week | 9 hours ✕ 4 | Work (8 hours) |
| Short week | 9 hours ✕ 4 | OFF |
Unlike the rotating 12-hour patterns used in plants and hospitals, the 9/80 is anchored to the weekday grid — weekends are always off, and the only moving part is which Friday is yours. That is also why half the office is perpetually confused about whether this is an "A Friday" or a "B Friday": the two crews (or the whole company) simply started their cycles on different Mondays.
9/80 by the numbers
- Cycle length: 14 days — 9 working days, 5 off
- Hours: 80 per two weeks (eight 9-hour days + one 8-hour Friday)
- 3-day weekends: 26 per year, every other week
- Longest stretch: 5 working days
- Day length: 9 hours plus lunch — typically about a 7am–4:30pm door-to-door day
The payroll trick behind the 8-hour Friday
US overtime law counts hours per workweek, and a naive 9/80 would put 44 hours in one week and 36 in the other. Employers avoid that by defining the payroll workweek to start (and end) in the middle of the worked Friday — four hours of that Friday close one workweek at exactly 40 hours, and the other four open the next. It is the reason the worked Friday is 8 hours, and the reason you should not casually swap which Friday you take off without HR's blessing.
A note on this calculator: it marks the nine working days of your cycle and treats each as a standard shift, so the calendar and off-Friday answers are exact. If you use the pay estimator with it, remember your real worked Friday is 8 hours rather than 9 — a small difference the estimate does not model.
Pros and cons workers actually report
What people love
- 26 three-day weekends a year without losing pay or accruing leave.
- Errands, appointments, and long trips fit into the off-Friday instead of eating vacation days.
- Quieter roads: a 9-hour day usually means commuting off-peak on both ends.
What people struggle with
- Nine-hour days make school pickup and weekday evenings tight.
- Meetings with the other crew's off-Friday (or with normal-schedule clients) get squeezed into four shared days.
- Swapping an off-Friday is bureaucratically painful because of the workweek-split rule above.
Using the calculator
Set the cycle start date to the Monday of your long week — the week you work Friday. The preview strip shows the next two weeks; if your off-Friday shows on the wrong week, use the flip control to swap them, then read the whole year off the calendar or export the .ics so your phone answers for you. Coming from a plant-style rotation instead? See the 2-2-3 (Panama) or 4 on 4 off guides — those cycles drift through the week, which changes everything about planning.
Frequently asked questions
What is a 9/80 work schedule?
A compressed schedule where you work 80 hours over 9 days instead of 10: Monday–Thursday you work nine hours, and Fridays alternate — one week you work Friday, the next you get it off. The result is a 3-day weekend every other week without reducing total hours.
How do I know which Friday I have off?
Your off-Friday always follows your short week (the Monday–Thursday week). Set the calculator on this page to the Monday of your LONG week — the week you work Friday — and it maps every off-Friday for the next 12 months. If the preview looks inverted, tap the flip button to swap your weeks.
Is the worked Friday 8 or 9 hours on a 9/80?
Eight. The classic 9/80 is eight 9-hour days plus one 8-hour Friday, which is exactly 80 hours over two weeks. Many employers even split their payroll workweek in the middle of that Friday so each workweek stays at exactly 40 hours and no overtime is triggered.
What is the difference between a 9/80 and a 4/10?
A 4/10 works four 10-hour days every week and takes the same day off weekly — 52 three-day weekends a year, but longer days. A 9/80 works slightly shorter 9-hour days and gets every other Friday off — 26 three-day weekends. Offices choose between them based on coverage needs and commute tolerance.
Who uses the 9/80 schedule?
It is most common in engineering, aerospace and defense, energy companies, and government offices — salaried or office-hourly environments that want a recruiting perk without cutting hours. It is rare in 24/7 operations, which lean on rotating 12-hour patterns instead.