Keyboard Maestro does not have any date parsing abilities (eg for parsing an arbitrary text date like "October 13, 2014"), but you can use a regular expression to break apart a numerical date (eg m/d/y format), or alternatively you can just ask for the date components. Here is an example that prompts for the date and then inserts it in a variety of formats, eg:
2014-10-13
10/13/2014
October 13, 2014
