ISO8601 date code example
Example 1: iso date
2021-01-05T11:48Z
Example 2: 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
Example 3: ISO 8601
YYYY-MM-DD'T'hh:mm:ss'Z'
Z is the ofset from the UTC timezone
it can be replaced with "(+/-)hh:mm"
if ofset is not specified, character 'Z' is in place instead
2021-01-01T01:01:01+01:00
2021-02-02T02:02:42.069-02:00
2021-03-03T03:03:03.3Z
20210404T040404Z