In PostgreSQL, I’m trying to convert a hour to local time zone.

My machine has UTC as timezone

show timezone;
UTC

why these queries return different answers?

SELECT '2024-07-01 00:00:00' at time zone 'PST' ;
2024-06-30 16:00:00

SELECT '2024-07-01 00:00:00' AT TIME ZONE 'UTC' AT TIME ZONE 'PST';
2024-07-01 08:00:00+00

thanks