WordPress Version: 4.6
/**
* Converts an iso8601 date to MySQL DateTime format used by post_date[_gmt].
*
* @since 1.5.0
*
* @param string $date_string Date and time in ISO 8601 format {@link https://en.wikipedia.org/wiki/ISO_8601}.
* @param string $timezone Optional. If set to GMT returns the time minus gmt_offset. Default is 'user'.
* @return string The date and time in MySQL DateTime format - Y-m-d H:i:s.
*/
function iso8601_to_datetime($date_string, $timezone = 'user')
{
$timezone = strtolower($timezone);
if ($timezone == 'gmt') {
preg_match('#([0-9]{4})([0-9]{2})([0-9]{2})T([0-9]{2}):([0-9]{2}):([0-9]{2})(Z|[\+|\-][0-9]{2,4}){0,1}#', $date_string, $date_bits);
if (!empty($date_bits[7])) {
// we have a timezone, so let's compute an offset
$offset = iso8601_timezone_to_offset($date_bits[7]);
} else {
// we don't have a timezone, so we assume user local timezone (not server's!)
$offset = HOUR_IN_SECONDS * get_option('gmt_offset');
}
$timestamp = gmmktime($date_bits[4], $date_bits[5], $date_bits[6], $date_bits[2], $date_bits[3], $date_bits[1]);
$timestamp -= $offset;
return gmdate('Y-m-d H:i:s', $timestamp);
} elseif ($timezone == 'user') {
return preg_replace('#([0-9]{4})([0-9]{2})([0-9]{2})T([0-9]{2}):([0-9]{2}):([0-9]{2})(Z|[\+|\-][0-9]{2,4}){0,1}#', '$1-$2-$3 $4:$5:$6', $date_string);
}
}