diff --git a/test/built-ins/Date/15.9.1.15-1.js b/test/built-ins/Date/15.9.1.15-1.js
index f712bffd6d..eef35a051e 100644
--- a/test/built-ins/Date/15.9.1.15-1.js
+++ b/test/built-ins/Date/15.9.1.15-1.js
@@ -7,15 +7,12 @@ description: >
     Date Time String Format - specified default values will be set for
     all optional fields(MM, DD, mm, ss and time zone) when they are
     absent
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
         var result = false;
         var expectedDateTimeStr = new Date(1970, 0, 1, 0, 0, 0, 0).toISOString();
         var dateObj = new Date("1970");
         var dateStr = dateObj.toISOString();
         result = dateStr === expectedDateTimeStr;
-        return result;
-    }
-runTestCase(testcase);
+
+assert(result, 'result !== true');
diff --git a/test/built-ins/Date/now/15.9.4.4-0-3.js b/test/built-ins/Date/now/15.9.4.4-0-3.js
index ff1749c444..324d8d7093 100644
--- a/test/built-ins/Date/now/15.9.4.4-0-3.js
+++ b/test/built-ins/Date/now/15.9.4.4-0-3.js
@@ -4,12 +4,8 @@
 /*---
 es5id: 15.9.4.4-0-3
 description: Date.now must exist as a function
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
-
         var fun = Date.now;
-        return (typeof (fun) === "function");
-    }
-runTestCase(testcase);
+
+assert.sameValue(typeof (fun), "function", 'typeof (fun)');
diff --git a/test/built-ins/Date/prototype/toISOString/15.9.5.43-0-11.js b/test/built-ins/Date/prototype/toISOString/15.9.5.43-0-11.js
index 6cc15fcd58..13a93f295d 100644
--- a/test/built-ins/Date/prototype/toISOString/15.9.5.43-0-11.js
+++ b/test/built-ins/Date/prototype/toISOString/15.9.5.43-0-11.js
@@ -7,16 +7,12 @@ description: >
     Date.prototype.toISOString - RangeError is not thrown when value
     of date is Date(1970, 0, 100000001, 0, 0, 0, -1), the time zone is
     UTC(0)
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
         var timeZoneMinutes = new Date().getTimezoneOffset() * (-1);
         var date, dateStr;
 
         date = new Date(1970, 0, 100000001, 0, 0 + timeZoneMinutes - 60, 0, -1);
         dateStr = date.toISOString();
 
-        return dateStr[dateStr.length - 1] === "Z";
-    }
-runTestCase(testcase);
+assert.sameValue(dateStr[dateStr.length - 1], "Z", 'dateStr[dateStr.length - 1]');
diff --git a/test/built-ins/Date/prototype/toISOString/15.9.5.43-0-12.js b/test/built-ins/Date/prototype/toISOString/15.9.5.43-0-12.js
index 594b5c2301..5d026d6ca6 100644
--- a/test/built-ins/Date/prototype/toISOString/15.9.5.43-0-12.js
+++ b/test/built-ins/Date/prototype/toISOString/15.9.5.43-0-12.js
@@ -7,16 +7,12 @@ description: >
     Date.prototype.toISOString - RangeError is not thrown when value
     of date is Date(1970, 0, 100000001, 0, 0, 0, 0), the time zone is
     UTC(0)
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
         var timeZoneMinutes = new Date().getTimezoneOffset() * (-1);
         var date, dateStr;
 
         date = new Date(1970, 0, 100000001, 0, 0 + timeZoneMinutes - 60, 0, 0);
         dateStr = date.toISOString();
 
-        return dateStr[dateStr.length - 1] === "Z";
-    }
-runTestCase(testcase);
+assert.sameValue(dateStr[dateStr.length - 1], "Z", 'dateStr[dateStr.length - 1]');
diff --git a/test/built-ins/Date/prototype/toISOString/15.9.5.43-0-4.js b/test/built-ins/Date/prototype/toISOString/15.9.5.43-0-4.js
index 947e5d480f..2b4e4c026a 100644
--- a/test/built-ins/Date/prototype/toISOString/15.9.5.43-0-4.js
+++ b/test/built-ins/Date/prototype/toISOString/15.9.5.43-0-4.js
@@ -6,13 +6,9 @@ es5id: 15.9.5.43-0-4
 description: >
     Date.prototype.toISOString - format of returned string is
     'YYYY-MM-DDTHH:mm:ss.sssZ', the time zone is UTC(0)
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
         var date = new Date(1999, 9, 10, 10, 10, 10, 10);
         var localDate = new Date(date.getTime() - date.getTimezoneOffset() * 60000);
 
-        return localDate.toISOString() === "1999-10-10T10:10:10.010Z";
-    }
-runTestCase(testcase);
+assert.sameValue(localDate.toISOString(), "1999-10-10T10:10:10.010Z", 'localDate.toISOString()');
diff --git a/test/built-ins/Date/prototype/toISOString/15.9.5.43-0-5.js b/test/built-ins/Date/prototype/toISOString/15.9.5.43-0-5.js
index 0a73b528c3..3df6f20c9e 100644
--- a/test/built-ins/Date/prototype/toISOString/15.9.5.43-0-5.js
+++ b/test/built-ins/Date/prototype/toISOString/15.9.5.43-0-5.js
@@ -6,11 +6,8 @@ es5id: 15.9.5.43-0-5
 description: >
     Date.prototype.toISOString - The returned string is the UTC time
     zone(0)
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
         var dateStr = (new Date()).toISOString();
-        return dateStr[dateStr.length - 1] === "Z";
-    }
-runTestCase(testcase);
+
+assert.sameValue(dateStr[dateStr.length - 1], "Z", 'dateStr[dateStr.length - 1]');
diff --git a/test/built-ins/Date/prototype/toJSON/15.9.5.44-0-1.js b/test/built-ins/Date/prototype/toJSON/15.9.5.44-0-1.js
index 4600c686e8..1796e5c426 100644
--- a/test/built-ins/Date/prototype/toJSON/15.9.5.44-0-1.js
+++ b/test/built-ins/Date/prototype/toJSON/15.9.5.44-0-1.js
@@ -4,13 +4,8 @@
 /*---
 es5id: 15.9.5.44-0-1
 description: Date.prototype.toJSON must exist as a function
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
   var f = Date.prototype.toJSON;
-  if (typeof(f) === "function") {
-    return true;
-  }
- }
-runTestCase(testcase);
+
+assert.sameValue(typeof(f), "function", 'typeof(f)');
diff --git a/test/built-ins/Date/prototype/toJSON/15.9.5.44-0-2.js b/test/built-ins/Date/prototype/toJSON/15.9.5.44-0-2.js
index 7fa161c1c9..aa8a77fe71 100644
--- a/test/built-ins/Date/prototype/toJSON/15.9.5.44-0-2.js
+++ b/test/built-ins/Date/prototype/toJSON/15.9.5.44-0-2.js
@@ -4,12 +4,6 @@
 /*---
 es5id: 15.9.5.44-0-2
 description: Date.prototype.toJSON must exist as a function taking 1 parameter
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
-  if (Date.prototype.toJSON.length === 1) {
-    return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue(Date.prototype.toJSON.length, 1, 'Date.prototype.toJSON.length');