1799638 - Date: wrong Daylight Saving start time "hh:59:59.001"

Reporter

Description

•

2 years ago

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:106.0) Gecko/20100101 Firefox/106.0

Steps to reproduce:

Past Daylight Saving Time (DST, Summer time) has wrong start time. DST should not start at "hh:59:59.001", but at "hh:00:00".

This issue has 2 ways to reproduce.

Reproduce by Firefox:

Set your computer time zone to "Asia/Tokyo".
Start F12 Developer Tools Javascript Console.
Execute following Javascript cases. (The last 2 lines are wrong)

console.log((new Date("1948-05-01T23:59:59"))); // Date Sat May 01 1948 23:59:59 GMT+0900 (Japan Standard Time)
console.log((new Date("1948-05-01T23:59:59")).getTimezoneOffset()); // -540
console.log((new Date("1948-05-01T23:59:59.000"))); // Date Sat May 01 1948 23:59:59 GMT+0900 (Japan Standard Time)
console.log((new Date("1948-05-01T23:59:59.000")).getTimezoneOffset()); // -540
// following case is NG
console.log((new Date("1948-05-01T23:59:59.001"))); // Date Sun May 02 1948 00:59:59 GMT+1000 (Japan Daylight Time)
// following case is NG
console.log((new Date("1948-05-01T23:59:59.001")).getTimezoneOffset()); // -600
console.log((new Date("1948-05-02T00:00:00"))); // Date Sun May 02 1948 01:00:00 GMT+1000 (Japan Daylight Time)
console.log((new Date("1948-05-02T00:00:00")).getTimezoneOffset()); // -600

Set your computer time zone to "America/New_York".
Start F12 Developer Tools Javascript Console.
Execute following Javascript cases.

console.log((new Date("1966-04-24T01:59:59"))); // Date Sun Apr 24 1966 01:59:59 GMT-0500 (Eastern Standard Time)
console.log((new Date("1966-04-24T01:59:59")).getTimezoneOffset()); // 300
console.log((new Date("1966-04-24T01:59:59.000"))); // Date Sun Apr 24 1966 01:59:59 GMT-0500 (Eastern Standard Time)
console.log((new Date("1966-04-24T01:59:59.000")).getTimezoneOffset()); // 300
// following case is NG
console.log((new Date("1966-04-24T01:59:59.001"))); // Date Sun Apr 24 1966 02:59:59 GMT-0400 (Eastern Daylight Time)
// following case is NG
console.log((new Date("1966-04-24T01:59:59.001")).getTimezoneOffset()); // 240
console.log((new Date("1966-04-24T02:00:00"))); // Date Sun Apr 24 1966 03:00:00 GMT-0400 (Eastern Daylight Time)
console.log((new Date("1966-04-24T02:00:00")).getTimezoneOffset()); // 240

Reproduce by SpiderMonkey:

Execute following commands

$ TZ=Asia/Tokyo ./mach run
 0:00.33 /home/user/moz/mozilla-unified/obj-x86_64-pc-linux-gnu/dist/bin/js
js> console.log((new Date("1948-05-01T23:59:59")))
Sat May 01 1948 23:59:59 GMT+0900 (Japan Standard Time)
js> console.log((new Date("1948-05-01T23:59:59")).getTimezoneOffset())
-540
js> console.log((new Date("1948-05-01T23:59:59.000")))
Sat May 01 1948 23:59:59 GMT+0900 (Japan Standard Time)
js> console.log((new Date("1948-05-01T23:59:59.000")).getTimezoneOffset())
-540
js> console.log((new Date("1948-05-01T23:59:59.001")))
Sun May 02 1948 00:59:59 GMT+1000 (Japan Daylight Time)
js> console.log((new Date("1948-05-01T23:59:59.001")).getTimezoneOffset())
-600

$ TZ=America/New_York ./mach run
 0:00.32 /home/user/moz/mozilla-unified/obj-x86_64-pc-linux-gnu/dist/bin/js
js> console.log((new Date("1966-04-24T01:59:59")))
Sun Apr 24 1966 01:59:59 GMT-0500 (Eastern Standard Time)
js> console.log((new Date("1966-04-24T01:59:59")).getTimezoneOffset())
300
js> console.log((new Date("1966-04-24T01:59:59.000")))
Sun Apr 24 1966 01:59:59 GMT-0500 (Eastern Standard Time)
js> console.log((new Date("1966-04-24T01:59:59.000")).getTimezoneOffset())
300
js> console.log((new Date("1966-04-24T01:59:59.001")))
Sun Apr 24 1966 02:59:59 GMT-0400 (Eastern Daylight Time)
js> console.log((new Date("1966-04-24T01:59:59.001")).getTimezoneOffset())
240

$ hg log
changeset:   714960:cf9bf33343df
bookmark:    autoland
tag:         tip
user:        Mozilla Releng Treescript <release+treescript@mozilla.org>
date:        Tue Nov 08 06:58:10 2022 +0000
summary:     no bug - Bumping Firefox l10n changesets r=release a=l10n-bump DONTBUILD CLOSED TREE

Actual results:

Actual results are described as above.

Expected results:

For "Asia/Tokyo":

console.log((new Date("1948-05-01T23:59:59"))); // Date Sat May 01 1948 23:59:59 GMT+0900 (Japan Standard Time)
console.log((new Date("1948-05-01T23:59:59")).getTimezoneOffset()); // -540
console.log((new Date("1948-05-01T23:59:59.000"))); // Date Sat May 01 1948 23:59:59 GMT+0900 (Japan Standard Time)
console.log((new Date("1948-05-01T23:59:59.000")).getTimezoneOffset()); // -540
// following case shows expected result
console.log((new Date("1948-05-01T23:59:59.001"))); // Date Sat May 01 1948 23:59:59 GMT+0900 (Japan Standard Time)
// following case shows expected result
console.log((new Date("1948-05-01T23:59:59.001")).getTimezoneOffset()); // -540
console.log((new Date("1948-05-02T00:00:00"))); // Date Sun May 02 1948 01:00:00 GMT+1000 (Japan Daylight Time)
console.log((new Date("1948-05-02T00:00:00")).getTimezoneOffset()); // -600

Set your computer time zone to "America/New_York".
Start F12 Developer Tools Javascript Console.
Execute following Javascript cases.

console.log((new Date("1966-04-24T01:59:59"))); // Date Sun Apr 24 1966 01:59:59 GMT-0500 (Eastern Standard Time)
console.log((new Date("1966-04-24T01:59:59")).getTimezoneOffset()); // 300
console.log((new Date("1966-04-24T01:59:59.000"))); // Date Sun Apr 24 1966 01:59:59 GMT-0500 (Eastern Standard Time)
console.log((new Date("1966-04-24T01:59:59.000")).getTimezoneOffset()); // 300
// following case is NG
console.log((new Date("1966-04-24T01:59:59.001"))); // Date Sun Apr 24 1966 01:59:59 GMT-0500 (Eastern Standard Time)
// following case is NG
console.log((new Date("1966-04-24T01:59:59.001")).getTimezoneOffset()); // 300
console.log((new Date("1966-04-24T02:00:00"))); // Date Sun Apr 24 1966 03:00:00 GMT-0400 (Eastern Daylight Time)
console.log((new Date("1966-04-24T02:00:00")).getTimezoneOffset()); // 240

Node.js returns correct getTimezoneOffset result.

Interestingly, Chrome returns correct getTimezoneOffset result, but returns incorrect DST notation (wrong "Japan Standard Time" or "Eastern Daylight Time").

FYI

https://github.com/eggert/tz/blob/2022f/asia#L2135
Rule Japan 1948 only - May Sat>=1 24:00 1:00 D

https://github.com/eggert/tz/blob/2022f/northamerica#L352
Rule NYC 1921 1966 - Apr lastSun 2:00 1:00 D

This issue seems to be related to IANA tz database "D" LETTER/S.

André Bargull [:anba]

Assignee

Comment 1

•

2 years ago

Attached file Bug 1799638 - Part 1: Round seconds towards the start-of-time in DateTimeInfo::toClampedSeconds(). r=dminor! — Details

Phabricator Automation

Updated

•

2 years ago

Assignee: nobody → andrebargull

Status: UNCONFIRMED → ASSIGNED

Ever confirmed: true

André Bargull [:anba]

Assignee

Comment 2

•

2 years ago

Attached file Bug 1799638 - Part 2: Add casts to avoid floating point math. r=dminor! — Details

Add explicit casts to ensure the operations are performed using integer instead
of floating point math. Existing assertions ensure there won't be integer overflows.

Depends on D161591

André Bargull [:anba]

Assignee

Comment 3

•

2 years ago

Thanks for the report and the easy to reproduce example code!

Bryan Thrall [:bthrall]

Updated

•

2 years ago

Severity: -- → S3

Priority: -- → P1

Bryan Thrall [:bthrall]

Updated

•

2 years ago

Blocks: sm-runtime

Pulsebot

Comment 4

•

2 years ago

Pushed by andre.bargull@gmail.com: https://hg.mozilla.org/integration/autoland/rev/dada805c432b Part 1: Round seconds towards the start-of-time in DateTimeInfo::toClampedSeconds(). r=dminor https://hg.mozilla.org/integration/autoland/rev/8e4d64161ddc Part 2: Add casts to avoid floating point math. r=dminor

Noemi Erli[:noemi_erli]

Comment 5

•

2 years ago

bugherder

https://hg.mozilla.org/mozilla-central/rev/dada805c432b
https://hg.mozilla.org/mozilla-central/rev/8e4d64161ddc

Status: ASSIGNED → RESOLVED

Closed: 2 years ago

status-firefox108: --- → fixed

Resolution: --- → FIXED

Target Milestone: --- → 108 Branch

Bogdan Maris, Desktop Test Engineering

Updated

•

2 years ago

Flags: qe-verify+

Daniel Bodea [:danibodea]

Comment 6

•

2 years ago

•

Edited

I've reproduced this issue in Firefox v107.0 and verified the fix in Beta v108.0b4 and Nightly v109.0a1 In Windows 10.

Test results:

Tokyo Time Zone:
- Release v107.0:
  - console.log((new Date("1948-05-01T23:59:59"))); -> Date Sat May 01 1948 23:59:59 GMT+0900 (Japan Standard Time) (CORRECT)
  - console.log((new Date("1948-05-01T23:59:59")).getTimezoneOffset()); -> -540 (CORRECT)
  - console.log((new Date("1948-05-01T23:59:59.000"))); -> Date Sat May 01 1948 23:59:59 GMT+0900 (Japan Standard Time) (CORRECT)
  - console.log((new Date("1948-05-01T23:59:59.000")).getTimezoneOffset()); -> -540 (CORRECT)
  - console.log((new Date("1948-05-01T23:59:59.001"))); -> Date Sun May 02 1948 00:59:59 GMT+1000 (Japan Daylight Time) (INCORRECT)
  - console.log((new Date("1948-05-01T23:59:59.001")).getTimezoneOffset()); -> -600 (INCORRECT)
  - console.log((new Date("1948-05-02T00:00:00"))); -> Date Sun May 02 1948 01:00:00 GMT+1000 (Japan Daylight Time) (CORRECT)
  - console.log((new Date("1948-05-02T00:00:00")).getTimezoneOffset()); -> -600 (CORRECT)
- Beta v108.0b4:
  - console.log((new Date("1948-05-01T23:59:59"))); -> Date Sat May 01 1948 23:59:59 GMT+0900 (Japan Standard Time) (CORRECT)
  - console.log((new Date("1948-05-01T23:59:59")).getTimezoneOffset()); -> -540 (CORRECT)
  - console.log((new Date("1948-05-01T23:59:59.000"))); -> Date Sat May 01 1948 23:59:59 GMT+0900 (Japan Standard Time) (CORRECT)
  - console.log((new Date("1948-05-01T23:59:59.000")).getTimezoneOffset()); -> -540 (CORRECT)
  - console.log((new Date("1948-05-01T23:59:59.001"))); -> Date Sat May 01 1948 23:59:59 GMT+0900 (Japan Standard Time) (CORRECTED!)
  - console.log((new Date("1948-05-01T23:59:59.001")).getTimezoneOffset()); -> -540 (CORRECTED!)
  - console.log((new Date("1948-05-02T00:00:00"))); -> Date Sun May 02 1948 01:00:00 GMT+1000 (Japan Daylight Time) (CORRECT)
  - console.log((new Date("1948-05-02T00:00:00")).getTimezoneOffset()); -> -600 (CORRECT)
- Nightly v109.0a1:
  - console.log((new Date("1948-05-01T23:59:59"))); -> Date Sat May 01 1948 23:59:59 GMT+0900 (Japan Standard Time) (CORRECT)
  - console.log((new Date("1948-05-01T23:59:59")).getTimezoneOffset()); -> -540 (CORRECT)
  - console.log((new Date("1948-05-01T23:59:59.000"))); -> Date Sat May 01 1948 23:59:59 GMT+0900 (Japan Standard Time) (CORRECT)
  - console.log((new Date("1948-05-01T23:59:59.000")).getTimezoneOffset()); -> -540 (CORRECT)
  - console.log((new Date("1948-05-01T23:59:59.001"))); -> Date Sat May 01 1948 23:59:59 GMT+0900 (Japan Standard Time) (CORRECTED!)
  - console.log((new Date("1948-05-01T23:59:59.001")).getTimezoneOffset()); -> -540 (CORRECTED!)
  - console.log((new Date("1948-05-02T00:00:00"))); -> Date Sun May 02 1948 01:00:00 GMT+1000 (Japan Daylight Time) (CORRECT)
  - console.log((new Date("1948-05-02T00:00:00")).getTimezoneOffset()); -> -600 (CORRECT)

Daniel Bodea [:danibodea]

Comment 7

•

2 years ago

•

Edited

I've reproduced this issue in Firefox v107.0 and verified the fix in Beta v108.0b4 and Nightly v109.0a1 In Ubuntu 22 for the other time zone exemplified.

Test results:

New York time zone:
- Release v107.0:
  - console.log((new Date("1966-04-24T01:59:59"))); -> Date Sun Apr 24 1966 01:59:59 GMT-0500 (Eastern Standard Time) (CORRECT)
  - console.log((new Date("1966-04-24T01:59:59")).getTimezoneOffset()); -> 300 (CORRECT)
  - console.log((new Date("1966-04-24T01:59:59.000"))); // Date Sun Apr 24 1966 01:59:59 GMT-0500 (Eastern Standard Time)
  - console.log((new Date("1966-04-24T01:59:59.000")).getTimezoneOffset()); -> 300 (CORRECT)
  - console.log((new Date("1966-04-24T01:59:59.001"))); -> Date Sun Apr 24 1966 02:59:59 GMT-0400 (Eastern Daylight Time) (INCORRECT)
  - console.log((new Date("1966-04-24T01:59:59.001")).getTimezoneOffset()); -> 240 (INCORRECT)
  - console.log((new Date("1966-04-24T02:00:00"))); -> Date Sun Apr 24 1966 03:00:00 GMT-0400 (Eastern Daylight Time) (CORRECT)
  - console.log((new Date("1966-04-24T02:00:00")).getTimezoneOffset()); -> 240 (CORRECT)
- Beta v108.0b4:
  - console.log((new Date("1966-04-24T01:59:59"))); -> Date Sun Apr 24 1966 01:59:59 GMT-0500 (Eastern Standard Time) (CORRECT)
  - console.log((new Date("1966-04-24T01:59:59")).getTimezoneOffset()); -> 300 (CORRECT)
  - console.log((new Date("1966-04-24T01:59:59.000"))); // Date Sun Apr 24 1966 01:59:59 GMT-0500 (Eastern Standard Time)
  - console.log((new Date("1966-04-24T01:59:59.000")).getTimezoneOffset()); -> 300 (CORRECT)
  - console.log((new Date("1966-04-24T01:59:59.001"))); -> Date Sun Apr 24 1966 01:59:59 GMT-0400 (Eastern Daylight Time) (CORRECTED!)
  - console.log((new Date("1966-04-24T01:59:59.001")).getTimezoneOffset()); -> 300 (CORRECTED!)
  - console.log((new Date("1966-04-24T02:00:00"))); -> Date Sun Apr 24 1966 03:00:00 GMT-0400 (Eastern Daylight Time) (CORRECT)
  - console.log((new Date("1966-04-24T02:00:00")).getTimezoneOffset()); -> 240 (CORRECT)
- Nightly v109.0a1:
  - console.log((new Date("1966-04-24T01:59:59"))); -> Date Sun Apr 24 1966 01:59:59 GMT-0500 (Eastern Standard Time) (CORRECT)
  - console.log((new Date("1966-04-24T01:59:59")).getTimezoneOffset()); -> 300 (CORRECT)
  - console.log((new Date("1966-04-24T01:59:59.000"))); // Date Sun Apr 24 1966 01:59:59 GMT-0500 (Eastern Standard Time)
  - console.log((new Date("1966-04-24T01:59:59.000")).getTimezoneOffset()); -> 300 (CORRECT)
  - console.log((new Date("1966-04-24T01:59:59.001"))); -> Date Sun Apr 24 1966 01:59:59 GMT-0400 (Eastern Daylight Time) (CORRECTED!)
  - console.log((new Date("1966-04-24T01:59:59.001")).getTimezoneOffset()); -> 300 (CORRECTED!)
  - console.log((new Date("1966-04-24T02:00:00"))); -> Date Sun Apr 24 1966 03:00:00 GMT-0400 (Eastern Daylight Time) (CORRECT)
  - console.log((new Date("1966-04-24T02:00:00")).getTimezoneOffset()); -> 240 (CORRECT)

Daniel Bodea [:danibodea]

Comment 8

•

2 years ago

Based on the last comments with detailed test results, I confirm this fix in Beta v108.0a4 and Nightly v109.0a1.

Status: RESOLVED → VERIFIED

status-firefox107: --- → affected

status-firefox108: fixed → verified

status-firefox109: --- → verified

Flags: qe-verify+

OS: Unspecified → All

Hardware: Unspecified → Desktop

Ryan VanderMeulen [:RyanVM]

Updated

•

2 years ago

status-firefox107: affected → wontfix

Bug 1799638 - Part 1: Round seconds towards the start-of-time in DateTimeInfo::toClampedSeconds(). r=dminor! 2 years ago André Bargull [:anba] 48 bytes, text/x-phabricator-request		Details \| Review
Bug 1799638 - Part 2: Add casts to avoid floating point math. r=dminor! 2 years ago André Bargull [:anba] 48 bytes, text/x-phabricator-request		Details \| Review

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Date: wrong Daylight Saving start time "hh:59:59.001"

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(Core :: JavaScript: Standard Library, defect, P1)

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(Reporter: god.doesnotnecessarilyplaydice, Assigned: anba)

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