Schedule view is not timezone-aware

[Kunsi]

This conference is in UTC+01:00 (Europe/London), but the streaming website does always show dates in Europe/Berlin (UTC+02:00 currently). This leads to confusion by visitors, because the site states "talk running since (time in 30 minutes)".

The shown talk title is correct however, so this is just a display issue, the detection of the running talk is not affected.

I presume this also happens on the schedule view under the video player, which is correct by accident if the browser timezone matches the conference timezone. The schedule view should always show the conference timezone, no matter which timezone the browser is in.

[saerdnaer]

previous installments of this event series used following hack:

https://github.com/voc/streaming-website/blob/master/configs/archive/emf2018/config.php#L3-L4

streaming-website/configs/archive/emf2018/config.php

Lines 3 to 4 in 9995dd4

	$prev_tz = date_default_timezone_get();
	date_default_timezone_set('Europe/London');

Should we extend the conferenceJSON class to do something similar based on the time_zone_name config option?

streaming-website/docs/config-schema.json

Lines 83 to 89 in 9995dd4

	"time_zone_name": {
	"title": "Zeitzone",
	"type": "string",
	"examples": ["Europe/Amsterdam", "Europe/Berlin"],
	"default": "Europe/Amsterdam",
	"pattern": "^([A-Z][a-z+]/[A-Z][a-z+]|UTC)$"
	},

[Kunsi]

Yeah, that would be ideal.

[iSchluff]

Should we extend the conferenceJSON class to do something similar based on the time_zone_name config option?

streaming-website/docs/config-schema.json

Lines 83 to 89 in 9995dd4

	"time_zone_name": {
	"title": "Zeitzone",
	"type": "string",
	"examples": ["Europe/Amsterdam", "Europe/Berlin"],
	"default": "Europe/Amsterdam",
	"pattern": "^([A-Z][a-z+]/[A-Z][a-z+]|UTC)$"
	},

Probably a good idea, although I would recommend sticking with camelCase like in other properties.

I presume this also happens on the schedule view under the video player, which is correct by accident if the browser timezone matches the conference timezone. The schedule view should always show the conference timezone, no matter which timezone the browser is in.

I have previously added some code to the schedule to correctly show the current time in the timezone of the event

streaming-website/model/Schedule.php

Line 315 in 9c71454

'offset' => $from->getOffset(),

streaming-website/assets/js/lustiges-script.js

Lines 237 to 242 in 9c71454

	const eventOffset = parseFloat($block.data('offset')) || 0;
	const eventTime = formatLocalTime(now, eventOffset);
	$now.find('.overlay').css('width', px);
	$now.find('.label').text("now (" + eventTime + ")");
	$time.text(eventTime + " (" + formatOffset(eventOffset) + ")");

Although I am open to suggestions on how to better show this. I would have liked to display the name of the event timezone, but that wasn't possible previously because the name is not in the schedule.
With the config suggested by @saerdnaer this would be possible