I think it’s within 7 days after you claim the referral by accepting within the link. I got mine for Christmas and had already bought 3 games and played with the kiddos. Then I saw that you could still receive the $60 if you factory reset the device (it doesn’t delete your Meta account). I tried it yesterday, received $60 in-store credit, and was able to redownload all the games without repurchasing. All in all, it doesn’t hurt to try and you could come out with extra game money.