You don't understand the startdates?
Take, for example, 20181101.1900
Let me stick some spaces in some helpful places:
2018 11 01 . 19 00
That better?
20181101 means 1st November 2018, and 1900 is in 24-hour clock format, IE 7:00PM
Stardates in the Star Trek universe work in an entirely different way. Wikipedia has a good explanation on how Stardates work.