As I and many others here can tell you, setting due dates is always a fickle matter. It's best to set a date when all you have left to do is test and polish. That way you can at least release a finished product (even if it's not 100% polished.)
Just keep at it and don't get pressured by due dates and stuff like that. Keep going at your normal pace and when it's out, it's out. :)