In Google Calendar, when you click on a date and enter an event, it just asks you to enter something into a text field and it’ll automatically interpret what you entered.
So like, I’ll enter dinner at 7PM, 7PM dinner, dinner 7PM, etc. the app would just understand what it is I’m typing.
How is this done?
Here’s something in PHP: http://blog.builtbyprime.com/php/adding-google-quick-add-to-anything-the-textdate-php-class.