The year 2015 ends on a Thursday, with Friday falling on Jan 1, 2016.
If your weekly or bi-weekly pay period ends on Friday, Jan 1, 2016, and you hand out pay checks on the Friday, the checks must be dated January 1, 2016.
You must be consistent when dating your pay checks! If it’s always on a Friday, it must remain on a Friday.
You should NOT change the date of these checks to Thursday Dec 31, 2015. Doing so would create an extra pay on the employees’ T4s for 2015, and employees would be short a pay on their T4s for 2016.
When you have weekly payroll, this issue will occur every 5th or 6th year. When you have bi-weekly payroll, it will occur every 11th year.
Furthermore, with weekly payroll there will be 53 pay periods every 5th or 6th year. With bi-weekly payroll, there will be 27 pay periods every 11th year.