timezone, how postgres deal with it?

["Anibal David Acosta" <aa@xxxxxxxxxxxx>]

This query returns false

 

select ('2012-11-20 17:00:00-02:00'::timestamp with time zone) = ('2012-11-20 18:00:00-03:00'::timestamp with time zone)

 

But are exactly same time

 

Why?

 

timestamp with timezone just show/hide time zone?

 

thanks