Just tell him you guys are the last of the time lords and when he gets old enough you'll travel through time and space in a police box!

let him watch highlander and tell him that's his secret grandpa

Let him enjoy it! Now is the time to explore your imagination a little bit too! When the excitement of being a time traveler wears down, try to explain it again then. :) No harm there!

Aren't we all?!

F No ones life here, this seems pretty hilarious. I can imagine someone saying to a kid "So, in spring we travel an hour into the future, and in fall, we travel an hour into the past." :D

That sounds way cooler than the truth though, "yeah I changed the clock cause...well idk somebody said it was a good idea."

I had something similar happen to me. I once tried to explain that I'd built a time machine to my friend, and now he thinks I've made a car that accounts for daylight saving times when driven fast enough.

Stretch this out as long as possible. It would be the greatest practical joke ever if you could convince him that you're time travelers until he's in middle or high school (I'd advise telling him that nobody else can ever know or it could upset the balance of time. That'll keep others from telling him the truth).

This is a good thing, use your powers responsibly

it happens...kids lol