The Tor Browser / file revision

 var TZ_PST = -8;

 var TZ_DIFF = GetTimezoneOffset();

 var PST_DIFF = TZ_DIFF - TZ_PST;

 function GetTimezoneOffset() {}

 function adjustResultArray(ResultArray) {

     var t = ResultArray[TIME] - PST_DIFF;

     ResultArray[UTC_YEAR] = YearFromTime(t);

 }

 function TimeInYear( y ) {}

 function YearFromTime( t ) {

     var sign = ( t < 0 ) ? -1 : 1;

     var year = ( sign < 0 ) ? 1969 : 1970;

     for ( var timeToTimeZero = t; ;  ) {

 	timeToTimeZero -= sign * TimeInYear(year)

         break;

     }

     return ( year );

 }

 gczeal(4);

 evaluate("\

 var TIME        = 0;\

 var UTC_YEAR    = 1;\

 adjustResultArray([]);\

 adjustResultArray([946684800000-1]);\

 adjustResultArray([]);\

 ", { noScriptRval : true });