diff -r 000000000000 -r 6474c204b198 js/public/Date.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/public/Date.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,35 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef js_Date_h
+#define js_Date_h
+
+#include "jstypes.h"
+
+namespace JS {
+
+// Year is a year, month is 0-11, day is 1-based.  The return value is
+// a number of milliseconds since the epoch.  Can return NaN.
+JS_PUBLIC_API(double)
+MakeDate(double year, unsigned month, unsigned day);
+
+// Takes an integer number of milliseconds since the epoch and returns the
+// year.  Can return NaN, and will do so if NaN is passed in.
+JS_PUBLIC_API(double)
+YearFromTime(double time);
+
+// Takes an integer number of milliseconds since the epoch and returns the
+// month (0-11).  Can return NaN, and will do so if NaN is passed in.
+JS_PUBLIC_API(double)
+MonthFromTime(double time);
+
+// Takes an integer number of milliseconds since the epoch and returns the
+// day (1-based).  Can return NaN, and will do so if NaN is passed in.
+JS_PUBLIC_API(double)
+DayFromTime(double time);
+
+} // namespace JS
+
+#endif /* js_Date_h */