diff --git a/harness/assertRelativeDateMs.js b/harness/assertRelativeDateMs.js
new file mode 100644
index 0000000000..20eb4b259c
--- /dev/null
+++ b/harness/assertRelativeDateMs.js
@@ -0,0 +1,21 @@
+// Copyright (C) 2015 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/**
+ * Verify that the given date object's Number representation describes the
+ * correct number of milliseconds since the Unix epoch relative to the local
+ * time zone (as interpreted at the specified date).
+ *
+ * @param {Date} date
+ * @param {Number} expectedMs
+ */
+function assertRelativeDateMs(date, expectedMs) {
+  var actualMs = date.valueOf();
+  var localOffset = date.getTimezoneOffset() * 60000;
+
+  if (actualMs - localOffset !== expectedMs) {
+    $ERROR(
+      'Expected ' + date + ' to be ' + expectedMs +
+      ' milliseconds from the Unix epoch'
+    );
+  }
+}
diff --git a/test/built-ins/Date/S15.9.3.1_A5_T1.js b/test/built-ins/Date/S15.9.3.1_A5_T1.js
index a6cd4e11a6..04eeb2b185 100644
--- a/test/built-ins/Date/S15.9.3.1_A5_T1.js
+++ b/test/built-ins/Date/S15.9.3.1_A5_T1.js
@@ -1,7 +1,7 @@
 // Copyright 2009 the Sputnik authors.  All rights reserved.
 // This code is governed by the BSD license found in the LICENSE file.
-
 /*---
+esid: sec-date-constructor
 info: >
     The [[Value]] property of the newly constructed object
     is set by following steps:
@@ -14,56 +14,29 @@ info: >
     TimeClip(UTC(Result(11)))
 es5id: 15.9.3.1_A5_T1
 description: 2 arguments, (year, month)
-includes:
-    - numeric_conversion.js
-    - Date_constants.js
-    - Date_library.js
+includes: [assertRelativeDateMs.js]
 ---*/
 
-if (-2211638400000 !== new Date(1899, 11).valueOf()) {
-  $ERROR("#1: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(1899, 11), -2211667200000);
 
-if (-2208960000000 !== new Date(1899, 12).valueOf()) {
-  $ERROR("#2: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(1899, 12), -2208988800000);
 
-if (-2208960000000 !== new Date(1900, 0).valueOf()) {
-  $ERROR("#3: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(1900, 0), -2208988800000);
 
-if (-2649600000 !== new Date(1969, 11).valueOf()) {
-  $ERROR("#4: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(1969, 11), -2678400000);
 
-if (28800000 !== new Date(1969, 12).valueOf()) {
-  $ERROR("#5: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(1969, 12), 0);
 
-if (28800000 !== new Date(1970, 0).valueOf()) {
-  $ERROR("#6: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(1970, 0), 0);
 
-if (944035200000 !== new Date(1999, 11).valueOf()) {
-  $ERROR("#7: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(1999, 11), 944006400000);
 
-if (946713600000 !== new Date(1999, 12).valueOf()) {
-  $ERROR("#8: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(1999, 12), 946684800000);
 
-if (946713600000 !== new Date(2000, 0).valueOf()) {
-  $ERROR("#9: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(2000, 0),  946684800000);
 
-if (4099795200000 !== new Date(2099, 11).valueOf()) {
-  $ERROR("#10: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(2099, 11), 4099766400000);
 
-if (4102473600000 !== new Date(2099, 12).valueOf()) {
-  $ERROR("#11: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(2099, 12), 4102444800000);
 
-if (4102473600000 !== new Date(2100, 0).valueOf()) {
-  $ERROR("#12: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(2100, 0), 4102444800000);
diff --git a/test/built-ins/Date/S15.9.3.1_A5_T2.js b/test/built-ins/Date/S15.9.3.1_A5_T2.js
index d090db6e23..d9e22b90e6 100644
--- a/test/built-ins/Date/S15.9.3.1_A5_T2.js
+++ b/test/built-ins/Date/S15.9.3.1_A5_T2.js
@@ -1,7 +1,7 @@
 // Copyright 2009 the Sputnik authors.  All rights reserved.
 // This code is governed by the BSD license found in the LICENSE file.
-
 /*---
+esid: sec-date-constructor
 info: >
     The [[Value]] property of the newly constructed object
     is set by following steps:
@@ -14,56 +14,29 @@ info: >
     TimeClip(UTC(Result(11)))
 es5id: 15.9.3.1_A5_T2
 description: 3 arguments, (year, month, date)
-includes:
-    - numeric_conversion.js
-    - Date_constants.js
-    - Date_library.js
+includes: [assertRelativeDateMs.js]
 ---*/
 
-if (-2209046400000 !== new Date(1899, 11, 31).valueOf()) {
-  $ERROR("#1: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(1899, 11, 31), -2209075200000);
 
-if (-2208960000000 !== new Date(1899, 12, 1).valueOf()) {
-  $ERROR("#2: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(1899, 12, 1), -2208988800000);
 
-if (-2208960000000 !== new Date(1900, 0, 1).valueOf()) {
-  $ERROR("#3: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(1900, 0, 1), -2208988800000);
 
-if (-57600000 !== new Date(1969, 11, 31).valueOf()) {
-  $ERROR("#4: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(1969, 11, 31), -86400000);
 
-if (28800000 !== new Date(1969, 12, 1).valueOf()) {
-  $ERROR("#5: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(1969, 12, 1), 0);
 
-if (28800000 !== new Date(1970, 0, 1).valueOf()) {
-  $ERROR("#6: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(1970, 0, 1), 0);
 
-if (946627200000 !== new Date(1999, 11, 31).valueOf()) {
-  $ERROR("#7: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(1999, 11, 31), 946598400000);
 
-if (946713600000 !== new Date(1999, 12, 1).valueOf()) {
-  $ERROR("#8: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(1999, 12, 1), 946684800000);
 
-if (946713600000 !== new Date(2000, 0, 1).valueOf()) {
-  $ERROR("#9: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(2000, 0, 1), 946684800000);
 
-if (4102387200000 !== new Date(2099, 11, 31).valueOf()) {
-  $ERROR("#10: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(2099, 11, 31), 4102358400000);
 
-if (4102473600000 !== new Date(2099, 12, 1).valueOf()) {
-  $ERROR("#11: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(2099, 12, 1), 4102444800000);
 
-if (4102473600000 !== new Date(2100, 0, 1).valueOf()) {
-  $ERROR("#12: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(2100, 0, 1), 4102444800000);
diff --git a/test/built-ins/Date/S15.9.3.1_A5_T3.js b/test/built-ins/Date/S15.9.3.1_A5_T3.js
index 885c686027..61127083a4 100644
--- a/test/built-ins/Date/S15.9.3.1_A5_T3.js
+++ b/test/built-ins/Date/S15.9.3.1_A5_T3.js
@@ -1,7 +1,7 @@
 // Copyright 2009 the Sputnik authors.  All rights reserved.
 // This code is governed by the BSD license found in the LICENSE file.
-
 /*---
+esid: sec-date-constructor
 info: >
     The [[Value]] property of the newly constructed object
     is set by following steps:
@@ -14,56 +14,29 @@ info: >
     TimeClip(UTC(Result(11)))
 es5id: 15.9.3.1_A5_T3
 description: 4 arguments, (year, month, date, hours)
-includes:
-    - numeric_conversion.js
-    - Date_constants.js
-    - Date_library.js
+includes: [assertRelativeDateMs.js]
 ---*/
 
-if (-2208963600000 !== new Date(1899, 11, 31, 23).valueOf()) {
-  $ERROR("#1: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(1899, 11, 31, 23), -2208992400000);
 
-if (-2208960000000 !== new Date(1899, 12, 1, 0).valueOf()) {
-  $ERROR("#2: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(1899, 12, 1, 0), -2208988800000);
 
-if (-2208960000000 !== new Date(1900, 0, 1, 0).valueOf()) {
-  $ERROR("#3: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(1900, 0, 1, 0), -2208988800000);
 
-if (25200000 !== new Date(1969, 11, 31, 23).valueOf()) {
-  $ERROR("#4: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(1969, 11, 31, 23), -3600000);
 
-if (28800000 !== new Date(1969, 12, 1, 0).valueOf()) {
-  $ERROR("#5: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(1969, 12, 1, 0), 0);
 
-if (28800000 !== new Date(1970, 0, 1, 0).valueOf()) {
-  $ERROR("#6: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(1970, 0, 1, 0), 0);
 
-if (946710000000 !== new Date(1999, 11, 31, 23).valueOf()) {
-  $ERROR("#7: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(1999, 11, 31, 23), 946681200000);
 
-if (946713600000 !== new Date(1999, 12, 1, 0).valueOf()) {
-  $ERROR("#8: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(1999, 12, 1, 0), 946684800000);
 
-if (946713600000 !== new Date(2000, 0, 1, 0).valueOf()) {
-  $ERROR("#9: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(2000, 0, 1, 0), 946684800000);
 
-if (4102470000000 !== new Date(2099, 11, 31, 23).valueOf()) {
-  $ERROR("#10: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(2099, 11, 31, 23), 4102441200000);
 
-if (4102473600000 !== new Date(2099, 12, 1, 0).valueOf()) {
-  $ERROR("#11: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(2099, 12, 1, 0), 4102444800000);
 
-if (4102473600000 !== new Date(2100, 0, 1, 0).valueOf()) {
-  $ERROR("#12: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(2100, 0, 1, 0), 4102444800000);
diff --git a/test/built-ins/Date/S15.9.3.1_A5_T4.js b/test/built-ins/Date/S15.9.3.1_A5_T4.js
index 29d9862385..8f6ad8022f 100644
--- a/test/built-ins/Date/S15.9.3.1_A5_T4.js
+++ b/test/built-ins/Date/S15.9.3.1_A5_T4.js
@@ -1,7 +1,7 @@
 // Copyright 2009 the Sputnik authors.  All rights reserved.
 // This code is governed by the BSD license found in the LICENSE file.
-
 /*---
+esid: sec-date-constructor
 info: >
     The [[Value]] property of the newly constructed object
     is set by following steps:
@@ -14,56 +14,29 @@ info: >
     TimeClip(UTC(Result(11)))
 es5id: 15.9.3.1_A5_T4
 description: 5 arguments, (year, month, date, hours, minutes)
-includes:
-    - numeric_conversion.js
-    - Date_constants.js
-    - Date_library.js
+includes: [assertRelativeDateMs.js]
 ---*/
 
-if (-2208960060000 !== new Date(1899, 11, 31, 23, 59).valueOf()) {
-  $ERROR("#1: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(1899, 11, 31, 23, 59), -2208988860000);
 
-if (-2208960000000 !== new Date(1899, 12, 1, 0, 0).valueOf()) {
-  $ERROR("#2: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(1899, 12, 1, 0, 0), -2208988800000);
 
-if (-2208960000000 !== new Date(1900, 0, 1, 0, 0).valueOf()) {
-  $ERROR("#3: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(1900, 0, 1, 0, 0), -2208988800000);
 
-if (28740000 !== new Date(1969, 11, 31, 23, 59).valueOf()) {
-  $ERROR("#4: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(1969, 11, 31, 23, 59), -60000);
 
-if (28800000 !== new Date(1969, 12, 1, 0, 0).valueOf()) {
-  $ERROR("#5: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(1969, 12, 1, 0, 0), 0);
 
-if (28800000 !== new Date(1970, 0, 1, 0, 0).valueOf()) {
-  $ERROR("#6: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(1970, 0, 1, 0, 0), 0);
 
-if (946713540000 !== new Date(1999, 11, 31, 23, 59).valueOf()) {
-  $ERROR("#7: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(1999, 11, 31, 23, 59), 946684740000);
 
-if (946713600000 !== new Date(1999, 12, 1, 0, 0).valueOf()) {
-  $ERROR("#8: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(1999, 12, 1, 0, 0), 946684800000);
 
-if (946713600000 !== new Date(2000, 0, 1, 0, 0).valueOf()) {
-  $ERROR("#9: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(2000, 0, 1, 0, 0), 946684800000);
 
-if (4102473540000 !== new Date(2099, 11, 31, 23, 59).valueOf()) {
-  $ERROR("#10: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(2099, 11, 31, 23, 59), 4102444740000);
 
-if (4102473600000 !== new Date(2099, 12, 1, 0, 0).valueOf()) {
-  $ERROR("#11: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(2099, 12, 1, 0, 0), 4102444800000);
 
-if (4102473600000 !== new Date(2100, 0, 1, 0, 0).valueOf()) {
-  $ERROR("#12: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(2100, 0, 1, 0, 0), 4102444800000);
diff --git a/test/built-ins/Date/S15.9.3.1_A5_T5.js b/test/built-ins/Date/S15.9.3.1_A5_T5.js
index b820849988..283f33c772 100644
--- a/test/built-ins/Date/S15.9.3.1_A5_T5.js
+++ b/test/built-ins/Date/S15.9.3.1_A5_T5.js
@@ -1,7 +1,7 @@
 // Copyright 2009 the Sputnik authors.  All rights reserved.
 // This code is governed by the BSD license found in the LICENSE file.
-
 /*---
+esid: sec-date-constructor
 info: >
     The [[Value]] property of the newly constructed object
     is set by following steps:
@@ -14,56 +14,29 @@ info: >
     TimeClip(UTC(Result(11)))
 es5id: 15.9.3.1_A5_T5
 description: 6 arguments, (year, month, date, hours, minutes, seconds)
-includes:
-    - numeric_conversion.js
-    - Date_constants.js
-    - Date_library.js
+includes: [assertRelativeDateMs.js]
 ---*/
 
-if (-2208960001000 !== new Date(1899, 11, 31, 23, 59, 59).valueOf()) {
-  $ERROR("#1: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(1899, 11, 31, 23, 59, 59), -2208988801000);
 
-if (-2208960000000 !== new Date(1899, 12, 1, 0, 0, 0).valueOf()) {
-  $ERROR("#2: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(1899, 12, 1, 0, 0, 0), -2208988800000);
 
-if (-2208960000000 !== new Date(1900, 0, 1, 0, 0, 0).valueOf()) {
-  $ERROR("#3: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(1900, 0, 1, 0, 0, 0), -2208988800000);
 
-if (28799000 !== new Date(1969, 11, 31, 23, 59, 59).valueOf()) {
-  $ERROR("#4: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(1969, 11, 31, 23, 59, 59), -1000);
 
-if (28800000 !== new Date(1969, 12, 1, 0, 0, 0).valueOf()) {
-  $ERROR("#5: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(1969, 12, 1, 0, 0, 0), 0);
 
-if (28800000 !== new Date(1970, 0, 1, 0, 0, 0).valueOf()) {
-  $ERROR("#6: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(1970, 0, 1, 0, 0, 0), 0);
 
-if (946713599000 !== new Date(1999, 11, 31, 23, 59, 59).valueOf()) {
-  $ERROR("#7: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(1999, 11, 31, 23, 59, 59), 946684799000);
 
-if (946713600000 !== new Date(1999, 12, 1, 0, 0, 0).valueOf()) {
-  $ERROR("#8: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(1999, 12, 1, 0, 0, 0), 946684800000);
 
-if (946713600000 !== new Date(2000, 0, 1, 0, 0, 0).valueOf()) {
-  $ERROR("#9: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(2000, 0, 1, 0, 0, 0), 946684800000);
 
-if (4102473599000 !== new Date(2099, 11, 31, 23, 59, 59).valueOf()) {
-  $ERROR("#10: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(2099, 11, 31, 23, 59, 59), 4102444799000);
 
-if (4102473600000 !== new Date(2099, 12, 1, 0, 0, 0).valueOf()) {
-  $ERROR("#11: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(2099, 12, 1, 0, 0, 0), 4102444800000);
 
-if (4102473600000 !== new Date(2100, 0, 1, 0, 0, 0).valueOf()) {
-  $ERROR("#12: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(2100, 0, 1, 0, 0, 0), 4102444800000);
diff --git a/test/built-ins/Date/S15.9.3.1_A5_T6.js b/test/built-ins/Date/S15.9.3.1_A5_T6.js
index 84550a6c3d..371c972116 100644
--- a/test/built-ins/Date/S15.9.3.1_A5_T6.js
+++ b/test/built-ins/Date/S15.9.3.1_A5_T6.js
@@ -1,7 +1,7 @@
 // Copyright 2009 the Sputnik authors.  All rights reserved.
 // This code is governed by the BSD license found in the LICENSE file.
-
 /*---
+esid: sec-date-constructor
 info: >
     The [[Value]] property of the newly constructed object
     is set by following steps:
@@ -14,56 +14,29 @@ info: >
     TimeClip(UTC(Result(11)))
 es5id: 15.9.3.1_A5_T6
 description: 7 arguments, (year, month, date, hours, minutes, seconds, ms)
-includes:
-    - numeric_conversion.js
-    - Date_constants.js
-    - Date_library.js
+includes: [assertRelativeDateMs.js]
 ---*/
 
-if (-2208960000001 !== new Date(1899, 11, 31, 23, 59, 59, 999).valueOf()) {
-  $ERROR("#1: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(1899, 11, 31, 23, 59, 59, 999), -2208988800001);
 
-if (-2208960000000 !== new Date(1899, 12, 1, 0, 0, 0, 0).valueOf()) {
-  $ERROR("#2: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(1899, 12, 1, 0, 0, 0, 0), -2208988800000);
 
-if (-2208960000000 !== new Date(1900, 0, 1, 0, 0, 0, 0).valueOf()) {
-  $ERROR("#3: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(1900, 0, 1, 0, 0, 0, 0), -2208988800000);
 
-if (28799999 !== new Date(1969, 11, 31, 23, 59, 59, 999).valueOf()) {
-  $ERROR("#4: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(1969, 11, 31, 23, 59, 59, 999), -1);
 
-if (28800000 !== new Date(1969, 12, 1, 0, 0, 0, 0).valueOf()) {
-  $ERROR("#5: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(1969, 12, 1, 0, 0, 0, 0), 0);
 
-if (28800000 !== new Date(1970, 0, 1, 0, 0, 0, 0).valueOf()) {
-  $ERROR("#6: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(1970, 0, 1, 0, 0, 0, 0), 0);
 
-if (946713599999 !== new Date(1999, 11, 31, 23, 59, 59, 999).valueOf()) {
-  $ERROR("#7: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(1999, 11, 31, 23, 59, 59, 999), 946684799999);
 
-if (946713600000 !== new Date(1999, 12, 1, 0, 0, 0, 0).valueOf()) {
-  $ERROR("#8: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(1999, 12, 1, 0, 0, 0, 0), 946684800000);
 
-if (946713600000 !== new Date(2000, 0, 1, 0, 0, 0, 0).valueOf()) {
-  $ERROR("#9: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(2000, 0, 1, 0, 0, 0, 0), 946684800000);
 
-if (4102473599999 !== new Date(2099, 11, 31, 23, 59, 59, 999).valueOf()) {
-  $ERROR("#10: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(2099, 11, 31, 23, 59, 59, 999), 4102444799999);
 
-if (4102473600000 !== new Date(2099, 12, 1, 0, 0, 0, 0).valueOf()) {
-  $ERROR("#11: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(2099, 12, 1, 0, 0, 0, 0), 4102444800000);
 
-if (4102473600000 !== new Date(2100, 0, 1, 0, 0, 0, 0).valueOf()) {
-  $ERROR("#12: Incorrect value of Date");
-}
+assertRelativeDateMs(new Date(2100, 0, 1, 0, 0, 0, 0), 4102444800000);
diff --git a/test/harness/assertRelativeDateMs.js b/test/harness/assertRelativeDateMs.js
new file mode 100644
index 0000000000..c8c08b3b67
--- /dev/null
+++ b/test/harness/assertRelativeDateMs.js
@@ -0,0 +1,80 @@
+// Copyright (C) 2016 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+description: >
+     Only passes when the provided date is exactly the specified number of
+     milliseconds from the Unix epoch
+includes: [assertRelativeDateMs.js]
+---*/
+
+var thrown;
+
+assertRelativeDateMs(new Date(1970, 0), 0);
+assertRelativeDateMs(new Date(1970, 0, 1, 0, 0, 0, 0), 0);
+assertRelativeDateMs(new Date(1970, 0, 1, 0, 0, 0, 1), 1);
+assertRelativeDateMs(new Date(1970, 0, 1, 0, 0, 0, -1), -1);
+assertRelativeDateMs(new Date(1970, 0, 1, 0, 0, 1, 0), 1000);
+assertRelativeDateMs(new Date(1970, 0, 1, 0, 0, -1, 0), -1000);
+assertRelativeDateMs(new Date(1970, 0, 1, 0, 2, 0, 0), 120000);
+assertRelativeDateMs(new Date(1970, 0, 1, 0, -2, 0, 0), -120000);
+assertRelativeDateMs(new Date(2016, 3, 12, 13, 21, 23, 24), 1460467283024);
+
+thrown = null;
+try {
+  assertRelativeDateMs(new Date(1), 0);
+} catch (err) {
+  thrown = err;
+}
+if (!thrown) {
+  $ERROR('Expected error, but no error was thrown.');
+} else if (thrown.constructor !== Test262Error) {
+  $ERROR('Expected error of type Test262Error.');
+}
+
+thrown = null;
+try {
+  assertRelativeDateMs(new Date(-1), 0);
+} catch (err) {
+  thrown = err;
+}
+if (!thrown) {
+  $ERROR('Expected error, but no error was thrown.');
+} else if (thrown.constructor !== Test262Error) {
+  $ERROR('Expected error of type Test262Error.');
+}
+
+thrown = null;
+try {
+  assertRelativeDateMs(new Date(1970, 0), 1);
+} catch (err) {
+  thrown = err;
+}
+if (!thrown) {
+  $ERROR('Expected error, but no error was thrown.');
+} else if (thrown.constructor !== Test262Error) {
+  $ERROR('Expected error of type Test262Error.');
+}
+
+thrown = null;
+try {
+  assertRelativeDateMs(new Date(1970, 0), -1);
+} catch (err) {
+  thrown = err;
+}
+if (!thrown) {
+  $ERROR('Expected error, but no error was thrown.');
+} else if (thrown.constructor !== Test262Error) {
+  $ERROR('Expected error of type Test262Error.');
+}
+
+thrown = null;
+try {
+  assertRelativeDateMs(new Date('invalid'), NaN);
+} catch (err) {
+  thrown = err;
+}
+if (!thrown) {
+  $ERROR('Expected error, but no error was thrown.');
+} else if (thrown.constructor !== Test262Error) {
+  $ERROR('Expected error of type Test262Error.');
+}