In the UK, if the 1st May isn’t the Monday, then the next Monday becomes a ‘bank holiday’ Traditionally means the banks don’t open, so no other businesses could get anything done - therefore National holiday. Now it means any big business with full time employment doesn’t open (9-5 M-F types) all the other stuff opens slightly reduced hours. The local corner shop, still full on as if nothing happened. So May 4th is no work this year.