Local time zone offset in PostgreSQL

问题

My web app stores all timestamps in UTC without time zones. I have a shell/psql script that returns a list of recent logins, and I want that script to display login times in the server's local time zone (which may vary depending on where the server is and with daylight savings).

To get an interval representing the difference between my database server's time zone and UTC, I'm currently using this hack:

SELECT age(now() at time zone 'UTC', now());

That works, but is there a more straightforward way?

There's a server configuration parameter called "timezone" that returns a valid timezone string, but I don't think it's possible to access those parameters in a query. (I guess that's a separate question, but an answer to it would resolve the time zone issue.)

回答1:

SELECT  current_setting('TIMEZONE')

This can be used in a query, however, this does not give a numerical difference.

Your solution is fine.

回答2:

To get # of seconds difference as an integer, I have used simply:

select extract( timezone from now() );

来源：https://stackoverflow.com/questions/2110216/local-time-zone-offset-in-postgresql