Could build it in theory based on first known event date?
Discussion
I think #[4] was thinking about some first 10k Damus badges
So he must have found a workaround for that I guess
db has a first seen date for events (since created_at can be forged). This was recently removed from nostr-rs-relay though so I'm relying on an old backup.
Protocol-level proofs would require open timestamps. I dunno if any client or relay implements this. Damus will in the future.
The “In before” NIP