Each heart used to take 24 hours, so a student who lost all five waited up to five days. Now one heart returns every 5 hours, and 24 hours after the first heart was lost they all come back at once (the owner's call). /api/user/hearts reports both times (nextRefillAt, fullRefillAt); an existing timer longer than 5 hours is shortened the first time it is read. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>