To trigger this ending, go to 1999 AD (Epoch, Bucket, or Black Omen) after getting the Epoch for the second time or after finishing all the side quests. For this ending, Crono must be dead. This unlocks All Movies; Monster Data - Present; Art Gallery. Variations:

If you killed Magus in your second meeting, Frog will be Glenn again.

If you did not enter the code in to the machine at Lucca's House to save her mother, she will be sitting instead of standing.

If you went to 1999 AD by way of the Epoch, Marle will fly off with balloons. If not, your cat(s) will disappear through the time gate.