What cause the time zone to change?

Answer 1

A time zone is a region of the Earth that has adopted the same standard time, usually referred to as the local time. Most adjacent time zones are exactly one hour apart, and by convention compute their local time as an offset from Greenwich (England) Mean Time.

See also
Mountain Standard Time Zone
Central Standard Time Zone
Eastern Standard Time Zone
Atlantic Standard Time Zone
Newfoundland Standard Time Zone
Retrieved from "http://en.wikipedia.org/wiki/Yukon_Standard_Time_Zone"

Answer 2

I think of it like this (very unscientific). Times are used in reference to the sun (think of a sun dial). The way sunlight moves across the earth makes all our days start at different times, and end at different times. The earth's spin never slows down or speeds up so we all have equal hours in our days, but our days just occur at different times. So to reference the times of all the places in the world we have time zones.

Answer 3

the movement of the earth