Actually, it is showing it for the top character but the rest are empty except for those online where it is show the Zone they are in twice instead of the Zone and then the Last On date.
Ever since the last patch, the Last On column stopped showing the date the toon was last on, but the zone the player is in, which is already a separate column. Oddly, 1 toon in our fellowship does show the date which is strange.
This was reported a while ago: https://forums.daybreakgames.com/eq...ships-window-not-showing-last-on-date.280969/
Merged threads. This is something that's currently being worked on. It should be fixed in the next update