Обсуждение: BUG #1058: unexpected output when using timezone() and to_char()

The following bug has been logged online:

Bug reference:      1058
Logged by:          Blake Crosby

Email address:      bcrosby@nm.cbc.ca

PostgreSQL version: 7.3.2

Operating system:   FreeBSD 5.1-RELEASE-p11

Description:        unexpected output when using timezone() and to_char()

Details:

select to_char(CURRENT_TIMESTAMP,'Day Mon DD YYYY HH24:MI:SS TZ');

returns:

              to_char
------------------------------------
 Wednesday Jan 21 2004 10:02:11 EST


however,

select to_char(timezone('PST',CURRENT_TIMESTAMP),' Day Mon DD YYYY
HH24:MI:SS TZ');

returns:

             to_char
----------------------------------
  Wednesday Jan 21 2004 07:07:44


Notice the Time zone field (specified by 'TZ' in the to_char) is missing
from the output.

"PostgreSQL Bugs List" <pgsql-bugs@postgresql.org> writes:
> however,
> select to_char(timezone('PST',CURRENT_TIMESTAMP),' Day Mon DD YYYY
> HH24:MI:SS TZ');
> returns:

>   Wednesday Jan 21 2004 07:07:44

> Notice the Time zone field (specified by 'TZ' in the to_char) is missing
> from the output.

This isn't a bug.  The timezone() function returns datatype timestamp
without time zone, so there is nothing that to_char could usefully
print.

            regards, tom lane