PostgreSQL function for getting total posix hours or minutes

total_posix_offests.sql

CREATE OR REPLACE FUNCTION posix_hours(val TIMESTAMPTZ) RETURNS INTEGER AS $$
  BEGIN
    RETURN (EXTRACT(EPOCH FROM (val - TIMESTAMPTZ '1970-01-01 00:00:00+00')) /
            EXTRACT(EPOCH FROM INTERVAL '1 hour'))::INT;
  END;
$$ LANGUAGE plpgsql;

CREATE OR REPLACE FUNCTION posix_minutes(val TIMESTAMPTZ) RETURNS INTEGER AS $$
  BEGIN
    RETURN (EXTRACT(EPOCH FROM (val - TIMESTAMPTZ '1970-01-01 00:00:00+00')) /
            EXTRACT(EPOCH FROM INTERVAL '1 minute'))::INT;
  END;
$$ LANGUAGE plpgsql;

These functions will get the total number of minutes or hours since the beginning of the POSIX epoch.