If you have some variable in your node object or somewhere else like [created] = 1328281634 then you need to convert this to date format you like, so you can do it
with line like this, where you choose custom date format
format_date($timestamp, 'custom', 'D, j M, Y \a\\t G:i' );or use some predefined date format on your site like
format_date($timestamp, 'small');
format_date($timestamp, 'large');For custom formating look here PHP Date