Adapt date test to be timezone independant.

test/mjsunit/date.js

Index: test/mjsunit/date.js
diff --git a/test/mjsunit/date.js b/test/mjsunit/date.js
index f74a13c692cceb3c5970894dc14113de0106c5de..fa43cbb43157eb3b8450ee2021492da4302913f9 100644
--- a/test/mjsunit/date.js
+++ b/test/mjsunit/date.js
@@ -190,13 +190,8 @@ assertTrue(isNaN(d.getTime()));
 
 
 // Test creation with obscure date values.
-var timezoneOffset = new Date().getTimezoneOffset();
-d = new Date(1970, 0, 1 + 100000001, -24, -timezoneOffset);
-assertFalse(isNaN(d.getTime()));
-assertEquals(8640000000000000, d.getTime())
-d = new Date(1970, 0, 1 - 100000001, 24, -timezoneOffset);
-assertFalse(isNaN(d.getTime()));
-assertEquals(-8640000000000000, d.getTime())
+assertEquals(8640000000000000, Date.UTC(1970, 0, 1 + 100000001, -24));
+assertEquals(-8640000000000000, Date.UTC(1970, 0, 1 - 100000001, 24));
 
 
 // Parsing ES5 ISO-8601 dates.