Make daylight saving a global option

But the global board time is also set as default when registering. Isn't this also a personal setting?

Touché
You're right, with the ability to set the default timezone for guests there needs to be the ability to toggle DST on/off to keep times in sync. The way you presented it originally made me think only of the affect on new registrations, not of the impact on guests and the board as a whole.

Is my proposal going to be incorporated or do you want me to write a patch first?

Thanks for clarification.

The patch I supplied didn't solve the primary problem. Here's a patch that uses the forum dst as default value in the registration process:

File: /register.php

Add below line 467:

$select_dst = isset($_POST['dst']) ? $_POST['dst'] : $forum_config['o_default_dst'];

Replace line 471 with:

<span class="fld-input"><input type="checkbox" id="fld<?php echo ++$forum_page['fld_count'] ?>" name="dst" <?php $select_dst ? 'checked="checked" ' : '') ?>/></span>

In the registration process the forum setting is used for the timezone, so why shouldn't it be used for DST?

I can't imagine a situation where someone living in a country with DST doesn't want to use it.

I actually misinterpreted the code: in just glancing at it, I thought it was being used to determine whether or not to enable DST when the form was submitted. But Reines noticed the actual problem which my post coincidentally happened to allude to.

I'm currently using punbb and noticing that people in some countries currently get the wrong time because the US is still in summer time but the UK is now in winter time

Would it not make more sense to adjust the time according to the clock of the local PC with client side javascript - so it would output something like

Post_time=now()-1.23 hours

and the browser would display the relevant time without all the users having to select a timezone at all.

It seems kind of poor to me that we force everyone to select a timezone but then still get it wrong for a couple of weeks every year because different countries switch DST on different days - this patch is an improvement but surely its something that can be automated.

Also I think that asking the time is not really a good first impression to have on the user signup page, it just makes me think WTF this system can't even figure out what time it is! (you could at least get it to default to something sensible)

This would also have the bonus effect that users who are not signed in would also see the correct times.

I appreciate that fluxBB is supposed to be lightweight but surely this would not need that much CPU?

Adjust for DST: Daylight savings is in effect (advance times by 1 hour)
That is what it says

yes I think thats the problem - the user is running a machine presumably with a clock and time saving set the way they like, why cant the board just read that automatically.

when the guests are in different countries there is no 'right' global setting.

That would be an extension, not part of the core. People disable Javascript, you can't rely on it 100%.