@nikitonsky Japan launches a Mars Rover. The landing is hard, so the computer reboots, the clock resets, and it sends a message with timestamp=0
While the message is being transferred to the Earth, the Japan Emperor dies, thus resetting the current year to 1.
A system that receives the message needs to display in a human-readable format when the message was produced (recomputing it if corrupted) and when it was received.