When do I have to file my Canadian tax return?

There are a number of dates during the year when Canadian tax returns are due to be filed or payments are due to be paid:
Income tax return
Generally, your return for the current tax year has to be filed on or before April 30, next year.

Self-employed persons
If you ran a business in the current tax year, your current year return has to be filed on or before June 15 of the following year. However, if you have a balance owing, you still have to pay it on or before April 30, next year.