If you or your spouse or common-law partner are self-employed, the last day to file your 2016 income tax return is June 15, 2017. If you do so by this date, you will not incur a late-filing penalty.
You will not, however, escape interest for unpaid balances owing.
As per legislation, any balances owing, on your income tax return are due on April 30 unless April 30 falls on a weekend.
Please note that because April 30, 2017 was a Sunday, the due date for balances owing on your 2016 return were due May 1, 2017.