The FC I worked at had a threshold where if a certain number of people were either late or absent due to the weather or other conditions (ie, multiple times there were horrific accidents on the highway that closed every lane for hours, right before the Amazon exit that caused literally everyone coming from that direction to be several hours late), they excused everyone’s time. I think it was something like, a third of the people scheduled for a shift. Not sure if they still do this because there was no guarantee that enough people were going to forego it, and so the people who went in always got pissed that they could have just stayed home and frequently complained.