Well... It's true that there is no format to feed ParseDate with, but that's actually more of
ParseDate goes a long way to understand almost whatever way to express a date you choose - inclusive thinks like 'two weeks after Christmas' - and it does it quite well. I'm using it for years and have no complaint on it so far.
Give the parser a date string that someone else can understand, and it will get it right. Forget about regexes or any complication - express tha date in a meaningful way and it will 'just work'.