If you’re playing chess travelling & change timezones should you add/subtract 1 hour to both clocks?

No, your local time is irrelevant - game time is what counts. Once the game starts, the clocks run down without any adjustment.
On the other hand, you may want to adjust your watch . . .

When you play a game of chess your clock isn’t a real clock. It is just a timer. It doesn’t matter what time it is IRL
If you’re playing chess on an airplane and go through different timezones should you add/subtract one hour to both clocks?
(subject has 100 character limit apparently which is why the questions a bit different here)
It's all relative.

bunny, you beat me to it. I was going to ask if the airplane could approach the speed of light, how would that affect the time controls?

So if you play chess on a roundabout in a playground and sit on the outside while it spins and your opponent sits in the centre you actually have fractionally less time than them.

So if you play chess on a roundabout in a playground and sit on the outside while it spins and your opponent sits in the centre you actually have fractionally less time than them.
This explains why Ding Liren and Carlsen disconnect so much. They are top GMs and are at the center of the chess world.

If you’re playing chess on an airplane and go through different timezones should you add/subtract one hour to both clocks?
(subject has 100 character limit apparently which is why the questions a bit different here)
Yes, but only if it means @knightscape007 runs out of time and loses

If you’re playing chess on an airplane and go through different timezones should you add/subtract one hour to both clocks?
(subject has 100 character limit apparently which is why the questions a bit different here)
Yes, but only if it means @knightscape007 runs out of time and loses
Good answer
If you’re playing chess on an airplane and go through different timezones should you add/subtract one hour to both clocks?
(subject has 100 character limit apparently which is why the questions a bit different here)