Display Login Date Format

The field wpm_login_date is a selectable field in the Markup screen.
this field is in usermeta and shows as a 10 digit value i.e (1274288424) for todays login 2010-05-19
The result of the display on the page is just as it is stored on the database.

How can it be displayed in a readable format i.e. (2010-05-19) ?

Having the last login date gives me a great measure of current users ... Thanks in advance

  Tom Westervelt