You don't understand the startdates?
Take, for example, 20190429.0000
Let me stick some spaces in some helpful places:
2019 04 29 . 00 00
That better?
20190429 means 29th April 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.