Is there a way to show the date (in addition to time) in the OS X lock screen?

This is what the default OS X lock screen, (if you have it set to require password on wake from sleep etc.), looks like:

By default it seems to only show the time in the top right-hand corner.

It would be great to have today's date handy as a reference in the screen as well - just like you can configure it.

Without finding a third-party lock screen app (that costs money), is there a command or setting to include the date in the OS X default lock screen?

Another option, which worked for me, was the following crontab entry, in root's crontab:

0 0 * * * defaults write /Library/Preferences/com.apple.loginwindow LoginwindowText "The date is `date '+%B %d, %Y'`"

This sets a message on the lock screen, including the date. It isn't as slick as including the date with the time in the corner, but it has the advantage of working at all (I couldn't get @konqui's answer to work for me), and it doesn't require installing any 3rd-party software.

If anyone is interested, I detailed the procedure in more depth on my blog, but the essence of the solution is posted here.

You may use Live Wallpaper App and setup it as a wallpaper which supports clock on wallpaper. It's not free but it's not expensive too.