…is the first day of the month immediately following the date on which you turn 65. If your 65th birthday is the first of the month, then it becomes your normal retirement date.
For example: if your 65th birthday is July 2nd, 2010, your normal retirement date is August 1st, 2010. If your 65th birthday is July 1st, 2010, your normal retirement date is July 1st, 2010.
When you turn 65, most of you will also begin receiving benefits from
Old Age Security and the Canada Pension Plan. 
If you have earned some pension in at least two Plan Years, you
can retire as early as age 55, but your pension will be subject to a
reduction.
You do not have to retire at age 65.
You can choose to postpone your retirement after your normal retirement
date, up to December 1st of the year in which you turn 71. If you have not
chosen to retire by then, your pension will begin anyway, and you will
be deemed to have retired. Your postponed pension will include pension
earned after age 65, up to your retirement date.
