diff --git a/test/built-ins/Date/prototype/toDateString/invalid-date.js b/test/built-ins/Date/prototype/toDateString/invalid-date.js
new file mode 100644
index 0000000000..30a01cda0c
--- /dev/null
+++ b/test/built-ins/Date/prototype/toDateString/invalid-date.js
@@ -0,0 +1,17 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-date.prototype.todatestring
+description: Invalid Dates are rendered as "Invalid Date"
+info: >
+  Date.prototype.toDateString ( )
+
+  ...
+  3. If tv is NaN, return "Invalid Date".
+  ...
+---*/
+
+assert.sameValue(new Date(NaN).toDateString(), "Invalid Date");
+
+
diff --git a/test/built-ins/Date/prototype/toTimeString/invalid-date.js b/test/built-ins/Date/prototype/toTimeString/invalid-date.js
new file mode 100644
index 0000000000..426dd9cb9d
--- /dev/null
+++ b/test/built-ins/Date/prototype/toTimeString/invalid-date.js
@@ -0,0 +1,17 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-date.prototype.totimestring
+description: Invalid Dates are rendered as "Invalid Date"
+info: >
+  Date.prototype.toTimeString ( )
+
+  ...
+  3. If tv is NaN, return "Invalid Date".
+  ...
+---*/
+
+assert.sameValue(new Date(NaN).toTimeString(), "Invalid Date");
+
+
diff --git a/test/built-ins/Date/prototype/toUTCString/invalid-date.js b/test/built-ins/Date/prototype/toUTCString/invalid-date.js
new file mode 100644
index 0000000000..774fd69d72
--- /dev/null
+++ b/test/built-ins/Date/prototype/toUTCString/invalid-date.js
@@ -0,0 +1,16 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-date.prototype.toutcstring
+description: Invalid Dates are rendered as "Invalid Date"
+info: >
+  Date.prototype.toUTCString ( )
+
+  ...
+  3. If tv is NaN, return "Invalid Date".
+  ...
+---*/
+
+assert.sameValue(new Date(NaN).toUTCString(), "Invalid Date");
+