I was looking around for a way to implement the Django AdminDateWidget/AdminTimeWidget but it seemed to be more trouble than its worth.
Looking around a few sites, the best I've found is "jQueryUI datetime". The demo page can be found here.
Syntax is incredibly simple.
$('#datetime').datetime({ value: '+1min' }); });
And that's it!
The good thing is that this is compatible with Django, as the date/time format is the same as the one which the DateTime field accepts, so you can still use the default validation of the Django fields in a form.