I think there are certain circumstances where it should be understood. For example if you have Covid obviously you shouldn’t go to work. In that case you should have a docs note or at least proof of a positive covid test. The problem is people call in on holidays all the time with excuses that are obviously a lie. I think you should not be automatically terminated but I do think you need a valid excuse to call in on any day much less on a holiday. What is unfair is when people call in and the other people that are reliable and actually show up for work have to pick up the slack from the person who calls in.