[tz] Number of active tz regions?

[Eric Muller]

On 7/17/2013 9:53 AM, David Patte ₯ wrote:
> Am I correct to say, that for every lat/lng there (theoretically) exists
> a zone in that country and/or region that represents its timezone rules
> since 1970;

I don't think it is meaningful to assign a zone to uninhabited regions. 
Antartica is a good example. In the maps I produced, I only gave points 
(for the bases), not polygons, and there are no polygons in Antarctica.

> I am looking at this from the perspective of timezone boundaries; that
> tz boundaries (theoretically) don't change unless new tz zones are
> created, or it is discovered that a latlng's clock 'rules' since 1970
> can be more accurately be described by a different tz zone?

There is the situation of changes in administrative boundaries, which do 
not always create new TZ timezones. For example, in 2000, the boundary 
between Saudi Arabia and Yemen was redefined 
(http://www.dur.ac.uk/ibru/publications/view/?id=170). It's unclear to 
me whether the areas that changed should have resulted in creating new 
TZ timezones, but they certainly have not.

Eric.