diff --git a/jerry-core/ecma/builtin-objects/ecma-builtin-date-prototype.cpp b/jerry-core/ecma/builtin-objects/ecma-builtin-date-prototype.cpp
index a02416b88..ff74197f9 100644
--- a/jerry-core/ecma/builtin-objects/ecma-builtin-date-prototype.cpp
+++ b/jerry-core/ecma/builtin-objects/ecma-builtin-date-prototype.cpp
@@ -55,7 +55,27 @@
 static ecma_completion_value_t
 ecma_builtin_date_prototype_to_string (ecma_value_t this_arg) /**< this argument */
 {
-  return ecma_date_object_to_string (this_arg, ECMA_DATE_LOCAL);
+  ecma_completion_value_t ret_value = ecma_make_empty_completion_value ();
+
+  ECMA_TRY_CATCH (prim_value,
+                  ecma_date_get_primitive_value (this_arg),
+                  ret_value);
+
+  ecma_number_t *prim_num_p = ecma_get_number_from_value (prim_value);
+
+  if (ecma_number_is_nan (*prim_num_p))
+  {
+    ecma_string_t *magic_str_p = ecma_get_magic_string (LIT_MAGIC_STRING_INVALID_DATE_UL);
+    ret_value = ecma_make_normal_completion_value (ecma_make_string_value (magic_str_p));
+  }
+  else
+  {
+    ret_value = ecma_date_value_to_string (*prim_num_p, ECMA_DATE_LOCAL);
+  }
+
+  ECMA_FINALIZE (prim_value);
+
+  return ret_value;
 } /* ecma_builtin_date_prototype_to_string */
 
 /**
@@ -1101,7 +1121,27 @@ ecma_builtin_date_prototype_set_utc_full_year (ecma_value_t this_arg, /**< this
 static ecma_completion_value_t
 ecma_builtin_date_prototype_to_utc_string (ecma_value_t this_arg) /**< this argument */
 {
-  return ecma_date_object_to_string (this_arg, ECMA_DATE_UTC);
+  ecma_completion_value_t ret_value = ecma_make_empty_completion_value ();
+
+  ECMA_TRY_CATCH (prim_value,
+                  ecma_date_get_primitive_value (this_arg),
+                  ret_value);
+
+  ecma_number_t *prim_num_p = ecma_get_number_from_value (prim_value);
+
+  if (ecma_number_is_nan (*prim_num_p))
+  {
+    ecma_string_t *magic_str_p = ecma_get_magic_string (LIT_MAGIC_STRING_INVALID_DATE_UL);
+    ret_value = ecma_make_normal_completion_value (ecma_make_string_value (magic_str_p));
+  }
+  else
+  {
+    ret_value = ecma_date_value_to_string (*prim_num_p, ECMA_DATE_UTC);
+  }
+
+  ECMA_FINALIZE (prim_value);
+
+  return ret_value;
 } /* ecma_builtin_date_prototype_to_utc_string */
 
 /**
@@ -1116,7 +1156,27 @@ ecma_builtin_date_prototype_to_utc_string (ecma_value_t this_arg) /**< this argu
 static ecma_completion_value_t
 ecma_builtin_date_prototype_to_iso_string (ecma_value_t this_arg) /**< this argument */
 {
-  return ecma_date_object_to_string (this_arg, ECMA_DATE_UTC);
+  ecma_completion_value_t ret_value = ecma_make_empty_completion_value ();
+
+  ECMA_TRY_CATCH (prim_value,
+                  ecma_date_get_primitive_value (this_arg),
+                  ret_value);
+
+  ecma_number_t *prim_num_p = ecma_get_number_from_value (prim_value);
+
+  if (ecma_number_is_nan (*prim_num_p))
+  {
+    ecma_string_t *magic_str_p = ecma_get_magic_string (LIT_MAGIC_STRING_INVALID_DATE_UL);
+    ret_value = ecma_make_normal_completion_value (ecma_make_string_value (magic_str_p));
+  }
+  else
+  {
+    ret_value = ecma_date_value_to_string (*prim_num_p, ECMA_DATE_UTC);
+  }
+
+  ECMA_FINALIZE (prim_value);
+
+  return ret_value;
 } /* ecma_builtin_date_prototype_to_iso_string */
 
 /**
diff --git a/jerry-core/ecma/builtin-objects/ecma-builtin-helpers-date.cpp b/jerry-core/ecma/builtin-objects/ecma-builtin-helpers-date.cpp
index 2a542b802..38c47b3a1 100644
--- a/jerry-core/ecma/builtin-objects/ecma-builtin-helpers-date.cpp
+++ b/jerry-core/ecma/builtin-objects/ecma-builtin-helpers-date.cpp
@@ -917,7 +917,9 @@ ecma_date_insert_num_with_sep (ecma_string_t **str_p, /**< input/output string *
  *
  * Used by:
  *        - The Date routine.
- *        - The ecma_date_object_to_string helper routine.
+ *        - The Date.prototype.toString routine.
+ *        - The Date.prototype.toISOString routine.
+ *        - The Date.prototype.toUTCString routine.
  *
  * @return completion value
  *         Returned value must be freed with ecma_free_completion_value.
@@ -926,63 +928,51 @@ ecma_completion_value_t
 ecma_date_value_to_string (ecma_number_t datetime_num, /**<datetime */
                            ecma_date_timezone_t timezone) /**< timezone */
 {
-  ecma_completion_value_t ret_value = ecma_make_empty_completion_value ();
+  ecma_string_t *output_str_p;
+  ecma_number_t milliseconds;
 
-  if (ecma_number_is_nan (datetime_num))
+  if (timezone == ECMA_DATE_LOCAL)
   {
-    ecma_string_t *magic_str_p = ecma_get_magic_string (LIT_MAGIC_STRING_INVALID_DATE_UL);
-    ret_value = ecma_make_normal_completion_value (ecma_make_string_value (magic_str_p));
+    datetime_num = ecma_date_local_time (datetime_num);
+    milliseconds = ecma_date_ms_from_time (datetime_num);
+    output_str_p = ecma_new_ecma_string_from_number (milliseconds);
+    ecma_date_insert_leading_zeros (&output_str_p, milliseconds, 3);
   }
-  else
+  else /* ECMA_DATE_UTC */
   {
-    ecma_string_t *output_str_p;
-    ecma_number_t milliseconds;
-
-    if (timezone == ECMA_DATE_LOCAL)
-    {
-      datetime_num = ecma_date_local_time (datetime_num);
-      milliseconds = ecma_date_ms_from_time (datetime_num);
-      output_str_p = ecma_new_ecma_string_from_number (milliseconds);
-      ecma_date_insert_leading_zeros (&output_str_p, milliseconds, 3);
-    }
-    else /* ECMA_DATE_UTC */
-    {
-      milliseconds = ecma_date_ms_from_time (datetime_num);
-      output_str_p = ecma_get_magic_string (LIT_MAGIC_STRING__EMPTY);
-      ecma_date_insert_num_with_sep (&output_str_p, milliseconds, LIT_MAGIC_STRING_Z_CHAR, 3);
-    }
-
-    ecma_number_t seconds = ecma_date_sec_from_time (datetime_num);
-    ecma_date_insert_num_with_sep (&output_str_p, seconds, LIT_MAGIC_STRING_DOT_CHAR, 2);
-
-    ecma_number_t minutes = ecma_date_min_from_time (datetime_num);
-    ecma_date_insert_num_with_sep (&output_str_p, minutes, LIT_MAGIC_STRING_COLON_CHAR, 2);
-
-    ecma_number_t hours = ecma_date_hour_from_time (datetime_num);
-    ecma_date_insert_num_with_sep (&output_str_p, hours, LIT_MAGIC_STRING_COLON_CHAR, 2);
-
-    ecma_number_t day = ecma_date_date_from_time (datetime_num);
-    ecma_date_insert_num_with_sep (&output_str_p, day, LIT_MAGIC_STRING_TIME_SEP_U, 2);
-
-    /*
-     * Note:
-     *      'ecma_date_month_from_time' (ECMA 262 v5, 15.9.1.4) returns a number from 0 to 11,
-     *      but we have to print the month from 1 to 12 for ISO 8601 standard (ECMA 262 v5, 15.9.1.15).
-     */
-    ecma_number_t month = ecma_date_month_from_time (datetime_num) + 1;
-    ecma_date_insert_num_with_sep (&output_str_p, month, LIT_MAGIC_STRING_MINUS_CHAR, 2);
-
-    ecma_number_t year = ecma_date_year_from_time (datetime_num);
-    ecma_date_insert_num_with_sep (&output_str_p, year, LIT_MAGIC_STRING_MINUS_CHAR, 4);
-
-    ret_value = ecma_make_normal_completion_value (ecma_make_string_value (output_str_p));
+    milliseconds = ecma_date_ms_from_time (datetime_num);
+    output_str_p = ecma_get_magic_string (LIT_MAGIC_STRING__EMPTY);
+    ecma_date_insert_num_with_sep (&output_str_p, milliseconds, LIT_MAGIC_STRING_Z_CHAR, 3);
   }
 
-  return ret_value;
+  ecma_number_t seconds = ecma_date_sec_from_time (datetime_num);
+  ecma_date_insert_num_with_sep (&output_str_p, seconds, LIT_MAGIC_STRING_DOT_CHAR, 2);
+
+  ecma_number_t minutes = ecma_date_min_from_time (datetime_num);
+  ecma_date_insert_num_with_sep (&output_str_p, minutes, LIT_MAGIC_STRING_COLON_CHAR, 2);
+
+  ecma_number_t hours = ecma_date_hour_from_time (datetime_num);
+  ecma_date_insert_num_with_sep (&output_str_p, hours, LIT_MAGIC_STRING_COLON_CHAR, 2);
+
+  ecma_number_t day = ecma_date_date_from_time (datetime_num);
+  ecma_date_insert_num_with_sep (&output_str_p, day, LIT_MAGIC_STRING_TIME_SEP_U, 2);
+
+  /*
+   * Note:
+   *      'ecma_date_month_from_time' (ECMA 262 v5, 15.9.1.4) returns a number from 0 to 11,
+   *      but we have to print the month from 1 to 12 for ISO 8601 standard (ECMA 262 v5, 15.9.1.15).
+   */
+  ecma_number_t month = ecma_date_month_from_time (datetime_num) + 1;
+  ecma_date_insert_num_with_sep (&output_str_p, month, LIT_MAGIC_STRING_MINUS_CHAR, 2);
+
+  ecma_number_t year = ecma_date_year_from_time (datetime_num);
+  ecma_date_insert_num_with_sep (&output_str_p, year, LIT_MAGIC_STRING_MINUS_CHAR, 4);
+
+  return ecma_make_normal_completion_value (ecma_make_string_value (output_str_p));
 } /* ecma_date_value_to_string */
 
 /**
- * Common function to create a time zone specific string for objects.
+ * Common function to get the primitive value of the Date object.
  *
  * Used by:
  *        - The Date.prototype.toString routine.
@@ -993,8 +983,7 @@ ecma_date_value_to_string (ecma_number_t datetime_num, /**<datetime */
  *         Returned value must be freed with ecma_free_completion_value.
  */
 ecma_completion_value_t
-ecma_date_object_to_string (ecma_value_t this_arg, /**< this argument */
-                            ecma_date_timezone_t timezone) /**< timezone */
+ecma_date_get_primitive_value (ecma_value_t this_arg) /**< this argument */
 {
   ecma_completion_value_t ret_value = ecma_make_empty_completion_value ();
 
@@ -1008,13 +997,16 @@ ecma_date_object_to_string (ecma_value_t this_arg, /**< this argument */
     ecma_object_t *obj_p = ecma_get_object_from_value (this_arg);
     ecma_property_t *prim_value_prop_p = ecma_get_internal_property (obj_p,
                                                                      ECMA_INTERNAL_PROPERTY_PRIMITIVE_NUMBER_VALUE);
-    ecma_number_t *prim_value_num_p = ECMA_GET_NON_NULL_POINTER (ecma_number_t,
-                                                                 prim_value_prop_p->u.internal_property.value);
-    ret_value = ecma_date_value_to_string (*prim_value_num_p, timezone);
+    JERRY_ASSERT (prim_value_prop_p != NULL);
+
+    ecma_number_t *prim_value_num_p = ecma_alloc_number ();
+    *prim_value_num_p = *ECMA_GET_NON_NULL_POINTER (ecma_number_t,
+                                                    prim_value_prop_p->u.internal_property.value);
+    ret_value = ecma_make_normal_completion_value (ecma_make_number_value (prim_value_num_p));
   }
 
   return ret_value;
-} /* ecma_date_object_to_string */
+} /* ecma_date_get_primitive_value */
 
 /**
  * @}
diff --git a/jerry-core/ecma/builtin-objects/ecma-builtin-helpers.h b/jerry-core/ecma/builtin-objects/ecma-builtin-helpers.h
index 6d4c9d244..f0103af64 100644
--- a/jerry-core/ecma/builtin-objects/ecma-builtin-helpers.h
+++ b/jerry-core/ecma/builtin-objects/ecma-builtin-helpers.h
@@ -122,7 +122,7 @@ extern void ecma_date_insert_num_with_sep (ecma_string_t **str_p,
                                            uint32_t length);
 
 extern ecma_completion_value_t ecma_date_value_to_string (ecma_number_t datetime_num, ecma_date_timezone_t timezone);
-extern ecma_completion_value_t ecma_date_object_to_string (ecma_value_t this_arg, ecma_date_timezone_t timezone);
+extern ecma_completion_value_t ecma_date_get_primitive_value (ecma_value_t this_arg);
 
 #endif /* !CONFIG_ECMA_COMPACT_PROFILE_DISABLE_DATE_BUILTIN */