Here I am creating a new To Do item.  In the “Date Due” field, watch what happens when I type “Monday” and press ENTER.  Remember that today is Saturday, June 6, 2009.

M-o-n-d-a-y <enter> June 8, 2009 <enter> <committed>.

Would anyone have been surprised if instead, any one of the following occurred?

• A popup chastised me for “Invalid format!”
• A popup chastised me for “Invalid format! Please use DD/MM/YYYY!”
• A date picker appeared, with the next months’ worth of Mondays highlighted, expressing its confusion over my ambiguity.
• A confirmation dialog appeared asking me if I really meant July 8th, 2009.  Yes/No/Cancel?

Probably not.

Now I’m not saying this free-form entry field for dates is a usability needle-mover, just that I was pleasantly surprised that when I said Monday, Apple Mail assumed I meant the following Monday.  By the way, Outlook 2007 makes the same assumption in the Tasks view.

As designers and developers, we need to have this courage of our convictions to say “Yes, this is a reasonable interpretation of that input” (tested, backed by research, etc.!), giving our solutions the same social presence as that had by a helpful assistant.  This means making reasonable assumptions when told what to do, and not harassing our users with needless confirmation.  In 2009, with the availability and power of development frameworks, there’s no excuse for it.