This is simple, probably already done before, and uses no special features as of yet undescovered.
In the char field, have it start a mission, say 100. The mission creates an invisible special ship, armor 0, with a death delay of several hundred. The goal of the mission is, of course, to destroy the ship. The onshipdone field contains A100 S100 S101. Mission 101 is autoaborting with a datepostinc of 1, and, to be fancy, Q*** in the onabord field where STR# *** is some greeting like "Good morning, captain."
The use here is clear, make it so when the player is spending ages in a system, he is really spending ages.
Im sure similar ideas have come up, I'm just going to say it out loud for anyone that hasn't figured it out on their own.