Shinwa thinks I've already been. I have looked at all my other quest grantor NPCs and they all show zero quests completed.
@ Solsticesprite FYI I posted it here 😊 https://subeta.net/forums.php/read/8581/Did-something-fail-to-reset-Post-here
If Shinwa resets for you later but not for other users, it's the 24 hour timer which runs parallel to the midnight timer.