In our case it's not enforced, and we're not under any 5 nines obligation.
On the other hand, we're a bunch of lazy sysadmins and don't prefer to work if it's not necessary. As a result, we design our systems for resilience, so any problem both doesn't get big, and can wait the next morning, or next Monday 99% of the time.
Also, we definitely love what we do, hence we sometimes choose to take some work off of our colleagues' hand on a slow night. So, I personally prefer to read a tech doc, learn something and apply to on our systems if I have nothing better to do instead of watching TV.
IOW, we're not losing sleep doing our job.
TL;DR: It's acceptability depends on the circumstances a lot. If the employer is abusing you with that stick, that's bad. Otherwise, I see no problem.
On the other hand, we're a bunch of lazy sysadmins and don't prefer to work if it's not necessary. As a result, we design our systems for resilience, so any problem both doesn't get big, and can wait the next morning, or next Monday 99% of the time.
Also, we definitely love what we do, hence we sometimes choose to take some work off of our colleagues' hand on a slow night. So, I personally prefer to read a tech doc, learn something and apply to on our systems if I have nothing better to do instead of watching TV.
IOW, we're not losing sleep doing our job.
TL;DR: It's acceptability depends on the circumstances a lot. If the employer is abusing you with that stick, that's bad. Otherwise, I see no problem.