You must show whether your game is using Earth Time or Kerbin Time. You can find this in the General Settings of your game.

1 Kerbin Year = 426 Kerbin Days 1 Kerbin Day = 6 Hours 1 Kerbin Year = 2556 Hours

1 Earth Year = 365 Earth Days 1 Earth Day = 24 Hours 1 Earth Year = 8760 Hours

EDIT: There is a limit to how long a speedrun can be on speedrun.com, which is 999 hours. That means if your speedrun is longer than 41 Earth Days (166 Kerbin Days), you won't be able to submit it unless I find some workaround

Also remember a new game starts on "Year 1 Day 1", so "Day 3" is 2 Kerbin days, or 12 hours.