How can I convert
2012-01-18T11:45:00+01:00 (ISO 8601) to 1326883500 (unixtimestamp) in PHP?
echo date("U",strtotime('2012-01-18T11:45:00+01:00'));
To convert from ISO 8601 to unixtimestamp :
strtotime('2012-01-18T11:45:00+01:00');
// Output : 1326883500
To convert from unixtimestamp to ISO 8601 (timezone server) :
date_format(date_timestamp_set(new DateTime(), 1326883500), 'c');
// Output : 2012-01-18T11:45:00+01:00
To convert from unixtimestamp to ISO 8601 (GMT) :
date_format(date_create('@'. 1326883500), 'c') . "\n";
// Output : 2012-01-18T10:45:00+00:00
To convert from unixtimestamp to ISO 8601 (custom timezone) :
date_format(date_timestamp_set(new DateTime(), 1326883500)->setTimezone(new DateTimeZone('America/New_York')), 'c');
// Output : 2012-01-18T05:45:00-05:00
来源：https://stackoverflow.com/questions/8908797/convert-iso-8601-to-unixtimestamp