You don't understand the startdates?
Take, for example, 19990720.1633
Let me stick some spaces in some helpful places:
1999 07 20 . 16 33
That better?
19990720 means 20th July 1999, and 1633 is in 24-hour clock format, IE 4:33PM
Stardates in the Star Trek universe work in an entirely different way. Wikipedia has a good explanation on how Stardates work.