Then they may go elsewhere, to someone not on a 9-5 monday-friday culture. Many now space people out (ie some on a w-th weekend) so the company can provide 7-day service at normal rates. I used to work in film/tv. 7-day service is a norm.
24-hour is harder, but when you have clients across different time zones, it is also a norm. Again, with big films scattering themselves across the globe, it is expected that someone in authority picks up 24/7 because your 3am is sometimes the client's 10am.
You can charge more for this, but the client doesn't want to hear complaints. You will be judged on service rendered for a given price. The firm down the street, the one who can provide people on a sunday without overtime, will win the next contract.
You may have misread what I wrote. I’m not at all opposed to flex time, work schedules that include the weekend, people preferring off work hours. If someone prefers to work weekends and have weekdays off, fine. If someone prefers 6x6.66 hours instead of 5x8, good with me. People that work on drilling platforms or on ships have even more extreme schedules. Still, this is all fundamentally different from constant availability for a single person.
24-hour is harder, but when you have clients across different time zones, it is also a norm. Again, with big films scattering themselves across the globe, it is expected that someone in authority picks up 24/7 because your 3am is sometimes the client's 10am.
You can charge more for this, but the client doesn't want to hear complaints. You will be judged on service rendered for a given price. The firm down the street, the one who can provide people on a sunday without overtime, will win the next contract.