You don't understand the startdates?
Take, for example, 19990505.1517
Let me stick some spaces in some helpful places:
1999 05 05 . 15 17
That better?
19990505 means 5th May 1999, and 1517 is in 24-hour clock format, IE 3:17PM
Stardates in the Star Trek universe work in an entirely different way. Wikipedia has a good explanation on how Stardates work.