11234 - new Date( Date.toLocaleString() ) fails to return the original date

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect, P2)

Description

[cbegle]

(This bug imported from BugSplat, Netscape's internal bugsystem.  It
was known there as bug #111818
http://scopus.netscape.com/bugsplat/show_bug.cgi?id=111818
Imported into Bugzilla on 08/04/99 01:40)


according to 15.9.3.8, passing a string to the date constructor should
parse the string as in date.parse.

however, parsing a string created by Date.toLocaleString() fails to return
the same date that the localeString came from.

// this is correct
js> new Date(PST_FEB_29_2000)
Tue Feb 29 00:00:00 GMT-0800 (PST) 2000

// shouldnt' this be 00:00:00 ?
js> (new Date(PST_FEB_29_2000)).toLocaleString()
February 29, 2000 12:00:00 AM PST

// off by 12 hours!
js> new Date(Date.parse((new Date(PST_FEB_29_2000)).toLocaleString()))
Tue Feb 29 12:00:00 GMT-0800 (PST) 2000

// also off by 12 hours
js> new Date((new Date(PST_FEB_29_2000)).toLocaleString())
Tue Feb 29 12:00:00 GMT-0800 (PST) 2000

Comment 1

[Mike McCabe]

Reviving fossil Bugzilla bugs.

Marking as assigned.

Comment 2

[Mike McCabe]

Marking as fixed.

First, we don't guarantee a roundtrip from toLocaleString...

Second, it looks like there was a problem with parsing 12:00 AM; bug 4088 fixed
that some months ago.  That also fixed our behaviour here, I think.

Some transcripts:

Linux -

js> d = new Date('Tue Feb 29 00:00:00 GMT-0800 (PST) 2000')
Tue Feb 29 00:00:00 GMT-0800 (PST) 2000
js> d.toLocaleString()
Tue Feb 29 00:00:00 2000
js> d = new Date('February 29, 2000 12:00:00 AM PST')
Tue Feb 29 00:00:00 GMT-0800 (PST) 2000


Windows NT 4.0

js> d = new Date('Tue Feb 29 00:00:00 GMT-0800 (PST) 2000')
Tue Feb 29 00:00:00 GMT-0800 (Pacific Standard Time) 2000
js> d.toLocaleString()
Tuesday, February 29, 2000 00:00:00
js> d2 = new Date(d.toLocaleString())
Tue Feb 29 00:00:00 GMT-0800 (Pacific Standard Time) 2000
js> d3 = new Date('February 29, 2000 12:00:00 AM PST')
Tue Feb 29 00:00:00 GMT-0800 (Pacific Standard Time) 2000

... so it looks like things are groovey.

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/8de33c3888a5
[components] Close https://github.com/mozilla-mobile/android-components/issues/11234: Re-introduce close support in TabsFeature