You can use it to prevent accepting dinner plans tho

Some things ought not be meddled with.

Sorry, I'm already full from Professor Hawking's party.

If they suggest using the time machine to keep plans just shame them for suggesting you abuse the laws of time for trivial social interaction.

So sorry, I've already been to that point in time, and it just happens to be a fixed event. Just can't do it without tearing the fabric of reality, sorry 😢

Great power comes with great responsibility