Excerpt from Government of Canada's Guide to Payroll Deductions and Remittances.
"Remittance due dates: In Chapter 8, you will find more information on remitting payroll deductions. It talks about the different remitter types and due dates, how to make a remittance, and the forms to use.
When the due date falls on a Saturday, a Sunday, or a public holiday recognized by the Canada Revenue Agency, we consider your payment to be on time if we receive it on the next business day. For a list of public holidays, go to Public holidays."
For full guide see: https://www.canada.ca/en/revenue-agency/services/forms-publications/publications/t4001-employers-guide-payroll-deductions-remittances/employers-guide-payroll-deductions-remittances.html