Re: timestamp with/without time zone

Peter Eisentraut <peter_e@gmx.net> writes:
> Thomas Lockhart writes:
>> SQL9x "timestamp" has no notion of time zones. PostgreSQL "timestamp"
>> does.

> AFAICT, it does not.  The value is stored in UTC (more or less) and is
> converted to the local time zone for display.  But a data type is defined
> in terms of storage, not display.

I think Thomas' point is mainly a syntactic one, that our timestamp type
will accept and display timezones --- which makes it compatible at the
I/O level with SQL-style TIMESTAMP WITH TIME ZONE.  But I don't find
that argument very persuasive.  An app that is expecting SQL-compliant
handling of the zone info will still be broken, only in subtle
hard-to-find ways instead of nice simple obvious ways.  IMHO we don't
support TIMESTAMP WITH TIME ZONE, and we really oughtn't give people the
impression that we do.  Whether what we have is better than the spec's
definition is irrelevant here; the point is that it's different.
        regards, tom lane