<html>
<head>
<base href="https://bugs.webkit.org/" />
</head>
<body><span class="vcard"><a class="email" href="mailto:steve.hruda@hexagongeospatial.com" title="Steve Hruda <steve.hruda@hexagongeospatial.com>"> <span class="fn">Steve Hruda</span></a>
</span> changed
<a class="bz_bug_link
bz_status_NEW "
title="NEW - Time zone bug"
href="https://bugs.webkit.org/show_bug.cgi?id=137003">bug 137003</a>
<br>
<table border="1" cellspacing="0" cellpadding="8">
<tr>
<th>What</th>
<th>Removed</th>
<th>Added</th>
</tr>
<tr>
<td style="text-align:right;">CC</td>
<td>
</td>
<td>steve.hruda@hexagongeospatial.com
</td>
</tr></table>
<p>
<div>
<b><a class="bz_bug_link
bz_status_NEW "
title="NEW - Time zone bug"
href="https://bugs.webkit.org/show_bug.cgi?id=137003#c6">Comment # 6</a>
on <a class="bz_bug_link
bz_status_NEW "
title="NEW - Time zone bug"
href="https://bugs.webkit.org/show_bug.cgi?id=137003">bug 137003</a>
from <span class="vcard"><a class="email" href="mailto:steve.hruda@hexagongeospatial.com" title="Steve Hruda <steve.hruda@hexagongeospatial.com>"> <span class="fn">Steve Hruda</span></a>
</span></b>
<pre>Hi,
from my point of view, that's a regression because of the following changeset.
<a href="http://trac.webkit.org/changeset/159892">http://trac.webkit.org/changeset/159892</a>
This changeset doesn't handles extrem values like midnight, where the offsetHour of the UTC time is 23 (one day before) and the local time is 1 o'clock (next day)
In case of all other OS systems you will see the same code -> <a href="http://trac.webkit.org/browser/trunk/Source/WTF/wtf/DateMath.cpp?annotate=blame#L495">http://trac.webkit.org/browser/trunk/Source/WTF/wtf/DateMath.cpp?annotate=blame#L495</a>
But there are two additional lines -> 497 & 497 which fixes this special case…
if (diff < 0)
diff += secondsPerDay;
That means ….
localSystemTime.wHour = 0;
offsetHour=23 … which causes a negative value … and the diff+=secondsPerDay ensures that the diff result would be one Hour instead of -23 hours
We’ve found the attached V8DateTests.js (renamed to .txt) and adjusted it a little bit to get the results logged in the browsers console.
As you can see at “ResulBeforeOurBugFix.txt” and “ResultAfterOurBugFix.txt”, we were able to fix 6 tests which failed before out bug fix.
assertEquals("Sat Oct 25 2014 23:00:00 GMT+0200 (W. Europe Daylight Time)",
(new Date(2014, 9, 25, 23, 0)).toString());
assertEquals("Sat, 25 Oct 2014 21:00:00 GMT",
(new Date(2014, 9, 25, 23, 0)).toUTCString());
assertEquals("Sat Oct 25 2014 23:59:00 GMT+0200 (W. Europe Daylight Time)",
(new Date(2014, 9, 25, 23, 59)).toString());
assertEquals("Sat, 25 Oct 2014 21:59:00 GMT",
(new Date(2014, 9, 25, 23, 59)).toUTCString());
assertEquals("Sun Oct 26 2014 00:00:00 GMT+0200 (W. Europe Daylight Time)",
(new Date(2014, 9, 26, 0, 0)).toString());
assertEquals("Sun Oct 26 2014 00:59:00 GMT+0200 (W. Europe Daylight Time)",
(new Date(2014, 9, 26, 0, 59)).toString());
In addition we found out that WebKit also have problems in case of Windows in case of the change from winter to summer time.
Winter to summer time:
assertEquals("Sun Mar 30 2014 03:00:00 GMT+0200 (W. Europe Daylight Time)",
(new Date(2014, 2, 30, 2, 0)).toString());
assertEquals("Sun, 30 Mar 2014 01:00:00 GMT",
(new Date(2014, 2, 30, 2, 0)).toUTCString());
assertEquals("Sun Mar 30 2014 03:59:00 GMT+0200 (W. Europe Daylight Time)",
(new Date(2014, 2, 30, 2, 59)).toString());
assertEquals("Sun, 30 Mar 2014 01:59:00 GMT",
(new Date(2014, 2, 30, 2, 59)).toUTCString());
Summer to winter time:
assertEquals("Sun Oct 26 2014 02:00:00 GMT+0200 (W. Europe Daylight Time)",
(new Date(2014, 9, 26, 2, 0)).toString());
assertEquals("Sun, 26 Oct 2014 00:00:00 GMT",
(new Date(2014, 9, 26, 2, 0)).toUTCString());
assertEquals("Sun Oct 26 2014 02:59:00 GMT+0200 (W. Europe Daylight Time)",
(new Date(2014, 9, 26, 2, 59)).toString());
assertEquals("Sun, 26 Oct 2014 00:59:00 GMT",
(new Date(2014, 9, 26, 2, 59)).toUTCString());
The attached DateMath.cpp.patch solves the first issue. The extrem value bug, winter to summer and summer to winter time is still open.
Regards,
Steve</pre>
</div>
</p>
<hr>
<span>You are receiving this mail because:</span>
<ul>
<li>You are the assignee for the bug.</li>
</ul>
</body>
</html>