Bug 138427

Summary: Incorrect timezone information used for British Standard time for 1970
Product: WebKit Reporter: Boris Zbarsky <bzbarsky>
Component: JavaScriptCoreAssignee: Nobody <webkit-unassigned>
Status: NEW ---    
Severity: Normal CC: ggaren, mark.lam, msaboff
Priority: P2    
Version: 528+ (Nightly build)   
Hardware: Unspecified   
OS: Unspecified   

Description Boris Zbarsky 2014-11-05 08:58:02 PST 
Consider this expression:

  (new Date(0)).toLocaleString()

When run in the UK timezone, JavaScriptCore returns:

  "January 1, 1970 at 1:00:00 AM GMT+1"

which is correct: at the time BST was GMT+1 due to he British Standard Time experiment; see http://en.wikipedia.org/wiki/British_Summer_Time#Periods_of_deviation

However this expression:

  +(new Date(1970, 0, 1))

returns 0 in JavaScriptCore, whereas the correct value is -3600000, because the provided date/time is in local time, which was one hour ahead of GMT in 1970.