The difference between the generated time using:
- the Default timezone setting; versus
- the UTC timezone
new Date().getTimezoneOffset();
get_option('gmt_offset');
/** PHP core **/
/** PHP via shell **/
ob_start();
system('date +"%z"');
$offset = ob_get_contents();
ob_end_clean();
echo $offset; // +0800
SELECT TIMEDIFF(NOW(),CONVERT_TZ(NOW(),@@session.time_zone,'+00:00'))
date +"%z"
# +0800