It outranks the fire drill

The mistake

A client sets its system clock forward to 2031 to trigger an expired-trial check, then sends a message without resetting the clock first. The message list sorts by timestamp and trusts the client-supplied clock time rather than server time, so the message is stamped 2031 and stored with that timestamp. Because no other message will have a later timestamp until the real date catches up, that single message stays sorted above every subsequent message indefinitely, and resetting the clock afterward does nothing to fix the already-persisted timestamp.