On Wednesday, July 18, 2018 at 1:36:47 AM UTC-6, Gerald Kelleher wrote:
we do not cheat the normal passage of time even when we now can experience noon
twice in one day by crossing the date line or travelling faster than the Earth
is turning at certain latitudes.

Yes, that is correct. Time zones don't change the fact that it's the same time
everywhere; due to the Earth being a globe, the *time of day* is different in
different places, so we call the same time by different names in different
places.

So noon GMT, when people are eating lunch in Britain, is also called 6 PM
Central Standard Time, when people are eating supper in Saskatchewan. A
different part of the daily cycle in the two locations, but the same moment in
time in both, as a transatlantic long-distance telephone call could prove.

John Savard