Q. My father filed for an extension for his 2016 tax return? When is the due date for his 2016 tax return?A. The due date is Monday, October 16, 2017. As long as your dad has the postmark, October 16th, the tax return is considered on-time.Q. What is the difference in social security benefits if I start at age 62 or wait till 67 or 70?A.