Stardates Explained - 20191003.2200

You don't understand the startdates?

Take, for example, 20191003.2200

Let me stick some spaces in some helpful places:

2019 10 03 . 22 00

That better?

20191003 means 3rd October 2019, and 2200 is in 24-hour clock format, IE 10:00PM

Stardates in the Star Trek universe work in an entirely different way. Wikipedia has a good explanation on how Stardates work.

Events on this stardate