You don't understand the startdates?
Take, for example, 20260515.2057
Let me stick some spaces in some helpful places:
2026 05 15 . 20 57
That better?
20260515 means 15th May 2026, and 2057 is in 24-hour clock format, IE 8:57PM
Stardates in the Star Trek universe work in an entirely different way. Wikipedia has a good explanation on how Stardates work.