How People in Western China Handles Beijing Time
In some ways, the very concept of time is a social construct. After all, it is by sheer convention of the centuries past that humans decided that, for instance, 7am means early morning and 7pm means dinner time. The number could have been entirely something else had those who were in charge of creating standard time notations chose otherwise. And because humans are so used to the idea of 7am and 7pm means the same thing everywhere, there came to be the idea of time zones.