"Timezone less events" migration for Facebook - facebook

Question

Facebook recently added timezone less events (https://developers.facebook.com/roadmap/#timezone-less-events) to its Developer roadmap which says
"Since this migration was originally created, we have added a timezone field to events which indicates the name of the timezone (as defined here) where the event is expected to happen. FYI, developers reading time in ISO 8601 should be supporting the full standard when reading event times. Most events return local times (no GMT offset), but in the future events likely will return other formats (namely date-only and precise)."
It works for dates in ISO 8601 format but if I get dates in epoch format I always get +7 hrs difference.
e.g.
https://graph.facebook.com/369000383135224 returns
{
"id": "369000383135224",
"owner": {
"name": "Horst Uwe Peter",
"id": "1117563687"
},
"name": "Event in Dublin time 10:25",
"start_time": "2012-05-04T10:25:00",
"end_time": "2012-05-04T11:25:00",
"timezone": "Europe/Dublin",
"location": "Dublin, Ireland",
"venue": {
"id": "110769888951990"
},
"privacy": "FRIENDS",
"updated_time": "2012-05-04T09:27:29+0000",
"type": "event"
}
and
http://graph.facebook.com/369000383135224?date_format=U returns
{
"id": "369000383135224",
"owner": {
"name": "Horst Uwe Peter",
"id": "1117563687"
},
"name": "Event in Dublin time 10:25",
"start_time": 1336152300, <== Fri, 04 May 2012 17:25:00 GMT
"end_time": 1336155900, <== Fri, 04 May 2012 18:25:00 GMT
"timezone": "Europe/Dublin",
"location": "Dublin, Ireland",
"venue": {
"id": "110769888951990"
},
"privacy": "FRIENDS",
"updated_time": 1336123649,
"type": "event"
}
and with FQL using GRAPH end point
graph.facebook.com/fql?q=SELECT eid, name, description, location, venue, start_time, end_time, update_time, creator, privacy FROM event WHERE eid = 369000383135224
{
"data": [
{
"eid": 369000383135224,
"name": "Event in Dublin time 10:25",
"description": "",
"location": "Dublin, Ireland",
"venue": {
"id": 110769888951990
},
"start_time": 1336152300, <== Fri, 04 May 2012 18:25:00 GMT
"end_time": 1336155900, <== Fri, 04 May 2012 18:25:00 GMT
"update_time": 1336123649,
"creator": 1117563687,
"privacy": "FRIENDS"
}
]
}
does that mean migration works only for ISO 8601 formatted dates? and has no affect on FQL or epoch date format?

Answer 1

My events on a page I administer have never returned a timezone.
What I have found is that event times entered in the frontend dialog are treated as local times in "America/Los_Angeles" (complete with the US Daylight Savings Time changes, so you'll see +6 in winter and +7 in summer) and are then converted to "UTC" for storage in the database.
For display I use the following php function to show the correct times and note on the page that the times are local to the event's location:
function fb_event_time_convert($fb_time) {
$origin_dtz = new DateTimeZone('UTC');
$remote_dtz = new DateTimeZone('America/Los_Angeles');
$fb_time_str = '#' . $fb_time;
$origin_dt = new DateTime($fb_time_str, $origin_dtz);
$remote_dt = new DateTime($fb_time_str, $remote_dtz);
$offset = $origin_dtz->getOffset($origin_dt) - $remote_dtz->getOffset($remote_dt);
return $fb_time - $offset;
}