Re: Why data of timestamptz does not store value of timezone passed to it?

On Thu, Aug 28, 2014 at 03:33:56PM -0400, Bruce Momjian wrote:
> On Thu, Aug 28, 2014 at 11:26:53AM -0700, Kevin Grittner wrote:
> > Steve Crawford <scrawford@pinpointresearch.com> wrote:
> > 
> > > I have always considered "timestamp with time zone" to be a bad
> > > description of that data type but it appears to be a carryover
> > > from the specs. It is really a "point in time"
> > 
> > I agree.  While what timestamptz implements is a very useful data
> > type, I think it was a very unfortunate decision to implement that
> > for the standard type name, instead of something more consistent
> > with the spec.  It seems very unlikely to change, though, because
> > so much existing production code would break.  :-(
> > 
> > Understandably, people do tend to expect that saving something into 
> > a column defined as TIMESTAMP WITH TIME ZONE will save a time zone 
> > with the timestamp, and in PostgreSQL it does not.
> 
> So the standard requires storing of original timezone in the data type? 
> I was not aware of that.
> 

I do not have a copy of the SQL 92 spec, but several references to the
spec mention that it defined the "time zone" as a format "SHH:MM" where
S represents the sign (+ or -), which seems to be what PostgreSQL uses.

Regards,
Ken