I had this come up in a project I am working on for a customer, and just answered a message on http://groups.yahoo.com/group/dotnetregex/ about time validation (nope, sorry, answered it somewhere else, suggested they use above list).

 

“The easiest input to validate is input that can't be wrong”.

 

Seems like a pretty silly thing to say, self evident to say the least.

 

So why is it that people still use text boxes for dates and times?  Why not use a tool like http://www.excentricsworld.com/CustomControls/CalendarPopupDemo.aspx for dates?  Very cool, you can set it to display as a label, click a button, chose your date and update the label.

 

For time it's a little more intensive, there are 1440 minutes in a given day, so we really don't want to have a drop down list with 1440 items (plus one as a default).  A digital clock isn't that bad:

 

H: 1-12 (or 0-23)

MTens: 0-6

MOnes: 0-9

AM/PM (or nothing if 0-23)

 

Taking a lot of ambiguity out of a user interface leads to less things to validate on the back end.

 

Every once in a while the obvious needs to be stated, and I'll do it if no one else will :)