I've heard nostr:npub1yzvxlwp7wawed5vgefwfmugvumtp8c8t0etk3g8sky4n0ndvyxesnxrf8q does scheduling. 

Note thought that drafts and scheduled posts are probably public somewhere on relay. So if this scheduling is about some big reveal of secret in the future, check if it is not saved in plaintext on some relay.