current_time( 'mysql' ) returns local site time: 2021-03-07 04:15:33
current_time( 'mysql', 1 ) returns GMT: 2021-03-07 09:15:33
current_time( 'timestamp' ) returns local site time: 2021-03-07 04:15:33current_time( 'timestamp', 1 ) returns GMT: 2021-03-07 09:15:33
