Stardates Explained - 20010109.1530

You don't understand the startdates?

Take, for example, 20010109.1530

Let me stick some spaces in some helpful places:

2001 01 09 . 15 30

That better?

20010109 means 9th January 2001, and 1530 is in 24-hour clock format, IE 3:30PM

Stardates in the Star Trek universe work in an entirely different way. Wikipedia has a good explanation on how Stardates work.