For the past few years apple's calendar app has used this concept of "create quick event" where the user types a sentence in a format that allows the application to separate the data, and create the event that you want.
When the user types in "Work between 5-9 on Friday" the application will add an event on Friday and is titled "work" and the time block will be 5-9.
I have been thinking about doing a similar input field for an internal app. It would be used to log calls to a customer that users are doing everyday for 8 hours a day.
Has anyone had any personal experience with such an input field? Or feel that this way of entering data is challenging for users?