
You don't understand the startdates?
Take, for example, 20190620.0000
Let me stick some spaces in some helpful places:
2019 06 20 . 00 00
That better?
20190620 means 20th June 2019, and 0000 is in 24-hour clock format, IE 12:00 midnight
Stardates in the Star Trek universe work in an entirely different way. Wikipedia has a good explanation on how Stardates work.