1246930 - Date.prototype.toLocaleString() increase date on one hour in Firefox ESR 38.6.0

Status: RESOLVED WORKSFORME

(Core :: JavaScript: Internationalization API, defect)

Description

[whatdoyouseedoc]

User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/47.0.2526.73 Safari/537.36

Steps to reproduce:

Version of Firefox where bug runs: Firefox ESR 38.6.0

In Firefox console type javascript code.

var d = new Date(Date.UTC(2016,0,1,0,0,0));
console.log(d);
console.log(d.toLocaleString());


Actual results:

Console output:

Date {Fri Jan 01 2016 03:00:00 GMT+0300 (Russia TZ 2 Standard Time)}
1/1/2016, 4:00:00 AM


Expected results:

Why toLocaleString() increase date on one hour?
I should say that this bug ain't appears in regular non-ESR Firefox (checked in 43.0.1)

Comment 1

[André Bargull [:anba]]

Firefox ESR 38 has reached it's end-of-life and has been superseded by Firefox ESR 45. The issue is no longer reproducible in Firefox ESR 45, because Fx45 uses a newer ICU release which contains the necessary updates for the Russian time zones (bug 1210165). Therefore resolving the issue as works-for-me.