date time iso 8601 format code example

Example: iso-8601

echo date('c'); //2021-02-03T21:42:51-08:00

echo date(DATE_ISO8601); //2021-02-03T21:42:51-0800

$datetime = new DateTime();
echo $datetime->format(DateTime::ATOM); //2021-02-03T21:42:51-08:00