`ng-change` is unfortunately over-eager: it fires on every keystroke (i.e. even when you're still typing a duration string that is not yet valid). We want a behavior more like the normal JS `change` event: fire only when the input is complete, like when the field loses focus or you press return.

http://stackoverflow.com/questions/11868393/angularjs-inputtext-ngchange-fires-while-the-value-is-changing has some approaches to achieve a fire-on-blur functionality by creating a special directive for that. Sounds kind of like a big hammer for too small of a problem. What do you think? I do want to avoid more direct jQuery DOM event handling though, so maybe that's what we should do.