The DatePicker lets users easily select valid dates.
Browsing through the years is possible.
No unix-like date limit (works with pre-1970 dates).
Choose from us, european or iso-date format.
Customize the look and feel.
Can be used with time too.
Multilingual (currently en/de/fr, create your own lang file).
Supports skins.
Allowed date ranges can be allowed.
Lots of settings and API methods.