Overtime pay for hourly workers...is it 40 hours per week or can an employer mess with the calculation (60 hours one week, 0 hours the next week)?

They aren’t working 100% of the time - it’s not possible for someone to work 24/7 for even a few days, much less a month or more. They may not be able to leave, but that doesn’t mean they are working and being paid for every minute. It’s hard to find out how many hours/days a week they typically work - I’ve seen some sites that say it’s typically 40 hours per week and others that say it’s normally 60. Similarly some places say that 8 hour shifts are normal but others say 12 hour shifts are normal.

The employer generally cannot average the number of hours worked over a period of multiple weeks (with exceptions for first responders) - but not every job is covered by FLSA - see here for a court decision that says a different group of oil workers are exempt from FLSA as they are “highly compensated employees”. And even for jobs that are covered by FLSA, there are varying ways to calculate the overtime and/or pay week - for example, the fluctuating workweek or setting the pay week to start/end
around noon on Friday to allow a 9/80 schedule.

When I worked for SJSU comp time was not always time and a half. Example if had a call back it was for 4 hours. But you only got time and half pay for the hours you worked. Example if I was called in on a Sat urday and worked 2 hours I would receive 2 hours pay at time and a half and 2 hours of comp time at straight time. Or if I was off mid week. Sick day, comp day or vacation day, and then had to work Saturday I would receive onlyh 8 hours of comp time at the straight time.

This provides something of a loophole. You could have someone who works 80 hours on one Sunday-Saturday interval, and then has the next Sunday through Saturday off, and repeat, if you put the end of their workweek on Wednesday. So one Wednesday through Tuesday, they’re working 40 hours at the end of the week, and then the next Wednesday through Tuesday, they’re working 40 hours at the start of the week.

Given the complexity and the power imbalance between workers and bosses, wage theft is pretty common. This article gives some details, and it includes not properly calculating or paying overtime.Want to be a criminal in America? Stealing billions is your best bet to go scot-free | Judd Legum | The Guardian

Define work. Crab fisherman and Navy Seals and possibly other Special Forces around the world, go days without sleep, constantly moving except for meals. Soldiers in combat, sometimes stay awake for days in heated combat. The body uses.food and adrenaline as a substitute for sleep.

Work is when you are doing whatever tasks your employer is paying you to do and any necessary preparation for those tasks, as well as anything that must be done after completing those tasks. There are a very few jobs where you get paid while you are asleep - but except for firefighters, the only ones I know of are in some supervised living facilities where staff must be present overnight but need not be awake.

As far as sleep - define “going without sleep for days”. The crab fishermen used to work around the clock when the derby style was used rather than the current quota , but the season only lasted a few days. Most of the descriptions I’ve seen refer to the fishermen working 18-20 hours a day in those days which would allow some time to sleep. And of course now that they use quotas rather than the derby system, there’s not the same pressure to catch as many crabs as possible as quickly as possible - which has apparently made the job much safer and that is surely at least in part because they are not s sleep-deprived.

Regarding Navy Seals , they do go 5.5 days without sleep during their training. They apparently later have shifts of 72 hours (3 days) on and 12 hours off. Of course, if a battle breaks out , they are not going to sleep.

I don’t know all the details of the scam* firefighters are running. We get OT only after 40 hours in a single pay week. But as previously mentioned we can take comp time (paid time off) in lieu of the OT pay. And it’s a sweet, sweet deal. By law we can accrue up to 6 weeks in a fiscal year. That means if I work a measly 160 hours of OT in a year at 1.5 I accrue 6 weeks comp. Very easy to do in this line of work.
Add that to vacation time, 12 paid holidays and 3 personal days and we can get up to 17 weeks a year off paid, depending on what amount of vaca time you are up to. Or you can take it all paid out and cash in. I don’t deny it is a sweetheart of benefit.

*I jest my brethren at the firehouse. They work 24 hour shifts it’s true. But sometimes they make shift switches with other firefighters and in the end get 9 days off in a row without touching their vacation time. My neighbor is on an engine company and I won’t see him for a couple days then he’s off work for a week and a half. He does this about 8 times a year then uses vacation to take half the summer off. That’s a pretty sweet deal itself.

You stated:

They aren’t working 100% of the time - it’s not possible for someone to work 24/7 for even a few days, much less a month or more.

Then you stated:

Work is when you are doing whatever tasks your employer is paying you to do and any necessary preparation for those tasks, as well as anything that must be done after completing those tasks. There are a very few jobs where you get paid while you are asleep - but except for firefighters, the only ones I know of are in some supervised living facilities where staff must be present overnight but need not be awake.

As people mentioned, the federal law is generally more than 40 hours a week for non-exempt, but states and different organizations may have different laws.
I think my local govt considers overtime for their plow drivers to be anything outside of 8am to 4pm on a weekday…so those drivers will be getting overtime pay, even if they don’t work 40hrs a week or even 8 hours a day (its likely also why I see them plowing mostly at weird and inconsistent snow amounts and times)

I’ll note, that a long time ago, my boss at the pizza restaurant didn’t understand this and thought our two week pay period allowed more slack. SO if the pay period ended on a Wednesday, he could work me 40hr Mon-Wed, than clock started again on Thursday. I tried a couple of times to tell him I was getting paid overtime, but he wouldn’t listen…I enjoyed my $600/week paychecks.

I work in oil and gas and have some experience work g on compensation structures for field personnel with appropriate lawyerly support.

In the past most field staff were paid a salary which was a sort of ‘keeper’ compensation thatwas set according to the work scope or your staff , some workers are on a regular rotation, some different functions can go weeks on end of busy work off shore then months of low level activity, and some spend most of the time not doing anything g, but when the phone rings need to be at the heliport in 2 hrs and be ready for so e tough hours.

On top of that the field team would get a ’ rig bonus’ for everyday offshore , with various add ons for the type of service being run. This daily rig rate would be anywhere between 30-80 % of the total annual compensation, and 200k a year for a busy senior MWD or directional driller was not outrageous.

So a driller or a roughneck would have a very predictable salary, an directional driler , MWD , completions hand quite a bit more variable and fishing hand, quite erratic.

Anyway the general goal was balance activity with compensation and ensure you were paying sufficient to keep the people you want in the industry. People looked at what was the minimum they needed in a quiet month to pay the bills and on a yearly basis was the total shit to cash ratio worth it for the work done and time away from home.

The FLSA took a whole new take on that , now for quite a while it was ignored , thi gs got busy , lawyers noticed and a whole set of ‘did you work for x and not get overtime’ placards went up.

So everyone had to rejig the compensation structure to be in compliance with the FLSA. Which is fine and well, just different.

So under FLSA you have to track hours worked , which means hours working. So you may be on a rig and if you have a 12 hr shift , you will get paid 12 hrs, the remaining 12 hrs , even though you are still on a rig, you are not working.
Sometimes shifts go longer and the hours have to be tracked.
Any hours over 40 hrs in a week must be paid at overtime rate.
When you come off the rig , that’s it, no work, no pay needs to be paid according to FLSA.
Land work the hours worked are generally hotel door to hotel door.

Now all that makes for a really complicated figuring out of what is the right hourly rate to get the total annual compensation to be worth it for field team to stay around.

But you can give a weekly guaranteed rate , so you could guarantee 10 20 60 hrs week at what ever rate you want, in effect giving a salary. BUT even if you guarantee 60 hrs a week and a given rate, any actual hours over 40 in a week MUST be paid at over time rates.
You also have to set an official start and end day of the week , so all kinds of complications happen as if the new week starts on sunday , you could work 84 hrs in 7 days, but only get 4 hrs overtime.

There is one other lever in the compensation, you can still add a day rig bonus of say 800 bucks a day.
Now that has to get added, but also has to be added as basically being a bump to the hourly pay rate for overtime calculations, so you kind of get it twice.
That said the overall hourly rate, guaranteed hours and offshore daily bonus are all calculated based on expected work load for that particular task so some where the employee gets paid sort of according to activity and also being paid for retention and the company has some sort of matching of the employee cost to revenue .
To be honest the FLSA structure kind of screwed a lot of people over in the downturns. Many people had guaranteed hours, but as that is at company discretion, it was taken away during the last downturn, so most people not working got zip when not on a rig. If they had been on salary that would have been a tougher thing to do.

One other complication is that a ‘management’ or professional role can be fuzzy to define and can depend on if the person doing the work is following procedures or making active discretionary decisions, or if the fall into a ‘highly compensated’ bracket. That determination could be enough to be on an exempt pay scheme.

Anyway that’s a long way to say, its complicated the FLSA sets the minimum standard , you can pay employees more and add in whatever you like and do what you need to do to keep people.

Or to actually answer the question, if you are working under the FLSA, if you work over 40 hrs within the designated start and end of the work week you must be paid overtime on those hours at the calculated hourly rate, no deferment or other nonsense.
There are rules on time engaged to wait , and time off even if you are still at the workplace which don’t count as work hours.
The employer is free to pay people more, even when not working but should take note as to how additional bonuses may be construed as increases to the hourly rate for overtime calculation purposes.
If you are actually crew of a ship flagged under a different nation other rules may apply, but rigs working in federal waters may not have that loophole.