Trying to display (YYYY-MM-DD) on calendar week view table headers

I have a calendar that is displaying a specific week and I want the date in YYYY-MM-DD format to display next to the day of the week (ex. Mon, 2013-06-05). I've tried referencing the $rows['date'] variable but nothing is rendered. I'm still looking into this throughout the issue reports but if someone knows how to do this, please let me know. Thanks