Originally Posted by
Digifiend
That's moot. In Priest's brief Justice League run, it was stated that Cyborg was a founder and that was five years ago... an issue later (due to blatant editorial meddling), suddenly it was 15 years ago and he wasn't a founder. No Justice, the event which followed, re-established Martian Manhunter being a founder instead, and that is was 15 years ago. Batman and Green Arrow have likely been active several years longer than the team though, and probably Superman and Wonder Woman too. Of course, if comics published in 1960 are set 15 years ago, then comics published in 1990 (a few years before Death of Superman and the marriage), should be about eight years ago in-universe.
One thing is certain - the mathematics doesn't work out.