647568 - Incorrect parsing of ISO 8601 date

Status: RESOLVED DUPLICATE of bug 1275502

(Core :: JavaScript Engine, defect)

Description

[kuvik3]

User-Agent:       Mozilla/5.0 (Windows NT 6.1; WOW64; rv:2.0) Gecko/20100101 Firefox/4.0
Build Identifier: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:2.0) Gecko/20100101 Firefox/4.0

If I use 

  new Date("2011-07-02")

to parse ISO 8601 date, Firefox should add missing time information as 00:00:00.000 in _local_ time zone, so when I ask for getUTCHours(), it should return "22" (I live in timezone +02:00)

Firefox 4 returns "0" instead, which is, I think, not correct.

- Chrome and Opera returns "22" correctly.
- IE9 also returns "0", but they incorrectly treat all date inputs without timezone set as UTC timezone.
- WebKit doesn't support Date(ISO8601 string) yet.

Reproducible: Always

Comment 1

[David Mandelin [:dmandelin]]

Confirmed.

Comment 3

[David Mandelin [:dmandelin]]

Attachment: Patch

Comment 4

[Jeff Walden [:Waldo]]

Comment on attachment 531653 [details] [diff] [review]
Patch

There's a bug here, but it's not that "2011-07-01" is interpreted as local time.  It's that it's not interpreted as UTC!  I think IE9 is the only browser with correct behavior here at present.

http://wiki.ecmascript.org/lib/exe/fetch.php?id=start&cache=cache&media=resources:tc39-2010-062-rev5p.pdf

According to the latest errata, if the time zone offset is absent, it is to be treated as "Z", which produces UTC.  So I think the right fix here is to remove the |isLocalTime| variable, its assignments, and its uses entirely.

Comment 5

[John Milner]

I agree with Jeff's reading of ECMA-262 edition 5.1, but that behavior actually contradicts ISO 8601:2004(E). I filed a bug on the ECMAScript tracker: https://bugs.ecmascript.org/show_bug.cgi?id=112

Comment 6

[Jeff Walden [:Waldo]]

Interesting!  Good to have other people looking at this stuff (presumably with more domain knowledge than I have?), thanks for catching that.

Comment 7

[André Bargull [:anba]]

This is the same issue as in bug 570179. bug 570179, comment 4 also points out the different behaviour between date-only and date-time forms, i.e. date-only forms get UTC as the default timezone whereas date-time forms without a timezone specifier get the local timezone.

Comment 8

[Allen Wirfs-Brock]

This is a known bug in the ES5 and %.1 spec. See https://bugs.ecmascript.org/show_bug.cgi?id=112 

The ES6 draft currently says "If the time zone offset is absent, the date-time is interpreted as a local time."