Adjusting the clock on the 2006 to 2011 Corolla is not documented anywhere in the manual. I stumbled across how to do it by pushing all the buttons. The process to adjust is not logical and so I figured I would document it for someone else.
My stereo looks like this:
To adjust the time you need to hold the 'AM' button and at the same time press the number '1' button to adjust the hour or the number '2' button to adjust the minute.
I hope this helps someone.