How many actual time zones are there on our planet?  I realize that
there are 24 divisions, but with some countries using only one (like
China- which spans about 5) and others observing :30 minute offsets
(Like Australia) what is the actual total number of time zones on the
Earth??

primitive-ga:

The Wikipedia entry for "Time Zones" provides a comprehensive
description of each of the 39 distinct time zones and contained areas:

http://en.wikipedia.org/wiki/Time_zones

As you have observed, not all governments choose to make use of all of
the time zones that would ideally cover their nation. It is because of
this, as well as ideosyncracies surround the use (or non-use) of
Daylight Savings Time, that there are so many 'time zones' in a world
that has nominally 24 hours in a day!

Regards,

aht-ga
Google Answers Researcher

Nice.  I had *just* heard about Wikipedia, but didn't think to look
there.  Thanks for the quick response.

I just counted 31 unique times at The World Clock - Time Zones -
sorted by time zone:
http://www.timeanddate.com/worldclock/custom.html?sort=2

I think this listing is a good way of addressing what you are asking,
but it would be a lot more complicated to give a definitive answer,
because fluctuations probably occur due to some places observing
savings time and others not.

"Remotes are commonplace; in most broadcast operations they are
usually only from a few locations, but this was not the case for the
New Year's extravaganza put on by ABC-TV, The Public Broadcast Service
(PBS) and the British Broadcasting Corporation (BBC). The daylong show
aired shots from 37 time zones around the world. Some time zones
follow neighboring zones by only half an hour."

http://www.findarticles.com/p/articles/mi_m0CVJ/is_2000_Feb/ai_62751183

I was only counting distinct times, because it is possible for two
neighboring time zones to have the same time, thanks to daylight
saving.