Sorry, I should have specified the US. I don't think we have any holidays that companies are required to give employees off.
Normally it’s time and a half on federal holidays for hourly workers in the US.
How does that work for a salaried person?
I'd assume they have extra pay reported on the following month. Same system as for extra hours (don't exactly for Canada but it's probably something like X percent more for hours worked after 22h) and work done on planned holidays (you went on holiday but got a work request)