Account Creation date Anyway to know it?

Check your email?

If you've joined since the match history feature started, you can choose Ashe as a champion and scroll all the way to the bottom to see your original tutorial (and its date). If you started before it, nope.

http://matchhistory.na.leagueoflegends.com/en/#match-details/NA1/1423399943/218533396?tab=overview

That's mine. :) 6/18/2014, my account's 1st bday is coming up. You can even see my original ign.

Test

weird...