In Ontario, employees get a day off with public holiday pay. If
the employee is required to work on the holiday, the employee must be paid regular wages and/or premium pay and/or get a substituted day off with pay at a later date.
This year, July 1 falls on a Sunday; thus the public holiday will be celebrated on Monday July 2.
Other provinces may have different guidelines. If you are dealing with employees in other locations check to be sure.