I know what you mean, how small do they make violins anyway?
In a 24/7/365 cargo operation for a hundred years the port chemists were on call to open their lab after hours and on weekends & holidays each time our ships came in, to operate the office no differently than when you get a vessel during the regular workday. But during regular office hours you definitely need to be there too. These ships are big and they don't always come in every day or on time very often. You get an ETA but very few things can make a vessel get there early, and many different things can delay a vessel, either case being unpredictable. For these call-outs excessive after-hours fees would be added to the nominal invoice, and good incentive pay would trickle down the food chain.
Statistically since there are only 45 office-hours in a 168-hour week, most of the vessels had always incurred call-outs.
After being in my own private practice for a while one day there was a little flood and lost everything I had worked for for 20 years.
I could recover better financially with a business than a home, and I couldn't keep both so I gave up domestic life and started staying in the lab.
Sure I was "homeless" but I had a roof over my head and I worked with what I had remaining, to survive attending to the vessels where I still had capability.
Since I was always there, I made a deal with a small contractor to get right to work whenever they needed it, charging only decent basic fees per vessel regardless of after-hours. They were expected to benefit by not passing on this arrangement to the ultimate clients who would still be charged after-hours premiums, which was most of the time.
It made survival possible and he was only revealing to clients that things were now covered 24/7 without having to wait for people to be called in. Within a few weeks all of the much bigger international operators in our ports had changed over to full 24 hr shift coverage along these lines just to compete with little old me, the homeless CEO.