Clearing input element causes error

[bghveding]

Hi,

Version: 2.0.1

Steps to reproduce

• Open picker and choose a date
• Clear datefield
• Check console for error

If you select a date, then clear the input field afterwards, an error is thrown on line 519:

picker.setValue(picker.date.getTime());

The error:

Uncaught TypeError: Object [object Object] has no method 'getTime' 

Line 517 seems to be the culprit:

if (picker.date.isValid)

[Eonasdan]

@bghveding check out the latest commit, should be fixed for ya.

[bghveding]

Works like a charm, @Eonasdan. Thanks a lot! :)