Leaderboard

Only if you have a Switch that has the same Nintendo Account as a hacked Switch, and you can transfer to save over via local communication. Else no

When you started your game, did you have your switch set to a particular date? The league card pulls it's 'registration date' from the date of your switch when you start your game. Aside from starting a new game w/ the date you want, there is no current way to change it in PKHex, but it's a request that is in AFAIK. Example, I wanted mine for Shield to match when I got Sword early, so I set my Switch date to the date when my Sword copy was started, and the registration date was the date I set it to on my Switch - November 13th 2019.

Seed != Life.