General Rules for Using SET TIME ZONE
The following rules apply to using SET TIME ZONE.
You can set the default time zone for a session or user by specifying either a numeric
offset from UTC or by specifying a time zone string literal.
The range of time zone displacements permissible is
The form for time zone displacement values is always INTERVAL HOUR TO MINUTE.
The time zone string is associated with a session or user, not a time zone displacement.
When a time zone displacement is needed in a request, that string plus a TIMESTAMP
value or a TIME value, depending on which is appropriate, is used to determine the
time zone displacement needed for a particular usage.