9/80 Compressed Work Schedule Calculator

The odd one out on this site

Every other pattern here — 4-on-4-off, 2-2-3, continental, DuPont — exists to keep a building staffed around the clock, seven days a week, with rotating teams splitting up nights nobody wants alone. The 9/80 isn't that at all. No night shift. No team offset. No round-the-clock cover to arrange. It's an office and engineering schedule, built for work that can simply wait until Monday — aerospace and defence, government contracting, professional services, technical teams. Doing anything with shift coverage — healthcare, a manufacturing line, emergency services — means the 9/80 almost certainly isn't yours, and one of the rotating patterns linked below will fit better.

Which means the comparison that actually matters here isn't to another shift pattern at all. It's to the standard Monday-to-Friday week most 9/80 workers came from. Same 80 hours over a fortnight, either way. The 9/80 just repackages them — 9 slightly longer days instead of 10 ordinary ones, with the day you saved banked as a fortnightly day off.

How the hours actually fall

Eight 9-hour days and one 8-hour day, across the fortnight. In practice: Monday to Thursday at 9 hours, both weeks, a full 8-hour Friday in one of them, that Friday off entirely in the other. Eight nines and an eight, 80 hours, over 9 working days. The 9-hour days are the bit you actually notice — often an extra hour tacked on at the end of an already long day, and that hour matters a lot more at 6pm after a commute than it ever looks on a spreadsheet. Most people settle into the rhythm within a couple of weeks. Worth knowing up front, though: the day off isn't free. You're paying for it in slightly longer days, not getting it handed to you.

The trade: a fortnightly three-day weekend

The prize is a day off every other week, stacked on top of the normal weekend — usually alternate Fridays, sometimes alternate Mondays, either way turning one weekend in two into a three-day one. A free weekday isn't the same thing as a free Saturday. It's when banks, dentists, garages and the council are actually open, so it soaks up the admin that would otherwise eat into your real weekend. Here's the catch, though: colleagues on a standard schedule are still working on your off-Friday, so the messages don't stop arriving unless you're disciplined about switching off properly. And if your off-day happens to land on a bank holiday, employers handle that overlap differently from one to the next — worth confirming with your manager rather than assuming either way.

People who actually get the most out of the 9/80 tend to be strict about protecting the off-day. Out-of-office on. Notifications down. Treated as properly off, not a half-day of quietly catching up on email. The pattern hands you the time. Keeping it genuinely yours is down to you.

Working out your 9/80 calendar

The calculator needs one thing from you: your reference week — the fortnight where you work the full Friday rather than taking it off. Set that and the whole year locks into place, with every 9-hour day, every off-day and your country's bank holidays laid out. Check any single date in the sidebar, then export to your phone once it looks right.

Quick answers

Which day do I get off, and how does it alternate? Usually every other Friday, sometimes alternate Mondays, cycling on a two-week loop, so the same weekday comes free once a fortnight. Whether it's this Friday or next depends on which week is your reference week — set that above and the calendar marks every off-day for the whole year.

Who actually uses the 9/80? Mostly office and engineering roles — aerospace and defence, government contracting, professional services, tech teams — where work happens in a predictable weekday window rather than needing continuous round-the-clock cover. You rarely see it in healthcare, manufacturing lines or emergency services for exactly that reason.

How do the hours compare to a standard week? Identical 80 hours over a fortnight either way — the 9/80 just repackages 10 standard days into 9 slightly longer ones, banking the difference as a day off. The 9-hour days are the part you actually feel, often an extra hour at the end of an already long day, so the day off isn't free — you're paying for it in longer days, not getting it for nothing.

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