Index: Doc/library/time.rst
===================================================================
--- Doc/library/time.rst	(revision 78371)
+++ Doc/library/time.rst	(working copy)
@@ -7,7 +7,7 @@
 
 
 This module provides various time-related functions. For related
-functionality, see also the :mod:`datetime` and :mod:`calendar` modules.
+functionality, see also the :mod:`datetime` module.
 
 Although this module is always available,
 not all functions are available on all platforms.  Most of the functions
@@ -77,10 +77,10 @@
   available).
 
 * The time value as returned by :func:`gmtime`, :func:`localtime`, and
-  :func:`strptime`, and accepted by :func:`asctime`, :func:`mktime` and
-  :func:`strftime`, may be considered as a sequence of 9 integers.  The return
-  values of :func:`gmtime`, :func:`localtime`, and :func:`strptime` also offer
-  attribute names for individual fields.
+  :func:`strptime`, and accepted by :func:`asctime`, :func:`mktime`,
+  :func:`timegm` and :func:`strftime`, may be considered as a sequence of 9 integers.
+  The return values of :func:`gmtime`, :func:`localtime`, and :func:`strptime`
+  also offer attribute names for individual fields.
 
   +-------+-------------------+---------------------------------+
   | Index | Attribute         | Values                          |
@@ -107,8 +107,8 @@
 
   Note that unlike the C structure, the month value is a range of 1-12, not 0-11.
   A year value will be handled as described under "Year 2000 (Y2K) issues" above.
-  A ``-1`` argument as the daylight savings flag, passed to :func:`mktime` will
-  usually result in the correct daylight savings state to be filled in.
+  A ``-1`` argument as the daylight savings flag, passed to :func:`mktime` or :func:`timegm`
+  will usually result in the correct daylight savings state to be filled in.
 
   When a tuple with an incorrect length is passed to a function expecting a
   :class:`struct_time`, or having elements of the wrong type, a :exc:`TypeError`
@@ -129,7 +129,7 @@
   | seconds since the epoch | :class:`struct_time` in | :func:`localtime`       |
   |                         | local time              |                         |
   +-------------------------+-------------------------+-------------------------+
-  | :class:`struct_time` in | seconds since the epoch | :func:`calendar.timegm` |
+  | :class:`struct_time` in | seconds since the epoch | :func:`timegm`          |
   | UTC                     |                         |                         |
   +-------------------------+-------------------------+-------------------------+
   | :class:`struct_time` in | seconds since the epoch | :func:`mktime`          |
@@ -213,7 +213,7 @@
    UTC in which the dst flag is always zero.  If *secs* is not provided or
    :const:`None`, the current time as returned by :func:`time` is used.  Fractions
    of a second are ignored.  See above for a description of the
-   :class:`struct_time` object. See :func:`calendar.timegm` for the inverse of this
+   :class:`struct_time` object. See :func:`timegm` for the inverse of this
    function.
 
    .. versionchanged:: 2.1
@@ -223,6 +223,18 @@
       If *secs* is :const:`None`, the current time is used.
 
 
+.. function:: timegm(t)
+
+   This is the inverse function of :func:`gmtime`.  Its argument is the
+   :class:`struct_time` or full 9-tuple (since the dst flag is needed; use ``-1``
+   as the dst flag if it is unknown) which expresses the time in UTC.
+   It returns a floating point number, for compatibility with :func:`time`.
+   If the input value cannot be represented as a valid time, either
+   :exc:`OverflowError` or :exc:`ValueError` will be raised (which depends on
+   whether the invalid value is caught by Python or the underlying C libraries).
+   The earliest date for which it can generate a time is platform-dependent.
+
+
 .. function:: localtime([secs])
 
    Like :func:`gmtime` but converts to local time.  If *secs* is not provided or
@@ -543,10 +555,6 @@
       Internationalization services.  The locale settings can affect the return values
       for some of  the functions in the :mod:`time` module.
 
-   Module :mod:`calendar`
-      General calendar-related functions.   :func:`timegm` is the inverse of
-      :func:`gmtime` from this module.
-
 .. rubric:: Footnotes
 
 .. [#] The use of ``%Z`` is now deprecated, but the ``%z`` escape that expands to the
Index: Lib/test/test_time.py
===================================================================
--- Lib/test/test_time.py	(revision 78371)
+++ Lib/test/test_time.py	(working copy)
@@ -22,6 +22,8 @@
                      == time.asctime(time.localtime(self.t)))
         self.assertTrue(long(time.mktime(time.localtime(self.t)))
                      == long(self.t))
+        self.assertTrue(long(time.timegm(time.gmtime(self.t)))
+                     == long(self.t))
 
     def test_sleep(self):
         time.sleep(1.2)
Index: Modules/timemodule.c
===================================================================
--- Modules/timemodule.c	(revision 78371)
+++ Modules/timemodule.c	(working copy)
@@ -382,6 +382,46 @@
 	return 1;
 }
 
+#if defined(HAVE_TIMEGM) || (defined(HAVE_MKTIME) && defined(HAVE_WORKING_TZSET))
+
+static PyObject *
+time_timegm(PyObject *self, PyObject *tup)
+{
+    struct tm buf;
+    time_t tt;
+    if (!gettmarg(tup, &buf))
+        return NULL;
+#if defined(HAVE_TIMEGM)
+    /* Use timegm function where available */
+    tt = timegm(&buf);
+#elif defined(HAVE_MKTIME) && defined(HAVE_WORKING_TZSET)
+    /* Fallback to mktime, taken from timegm(3)*/
+    char *tz;
+    tz = getenv("TZ");
+    setenv("TZ", "", 1);
+    tzset();
+    tt = mktime(&buf);
+    if (tz)
+        setenv("TZ", "", 1);
+    else
+        unsetenv("TZ");
+    tzset();
+#endif
+    if (tt == (time_t)(-1)) {
+		PyErr_SetString(PyExc_OverflowError,
+				"timegm argument out of range");
+		return NULL;
+	}
+    return PyFloat_FromDouble((double)tt);
+}
+
+PyDoc_STRVAR(timegm_doc,
+"timegm(tuple) -> Floating point number\n\
+\n\
+Convert a UTC tuple to seconds since the Epoch.");
+
+#endif
+
 #ifdef HAVE_STRFTIME
 static PyObject *
 time_strftime(PyObject *self, PyObject *args)
@@ -773,6 +813,9 @@
 	{"localtime",	time_localtime, METH_VARARGS, localtime_doc},
 	{"asctime",	time_asctime, METH_VARARGS, asctime_doc},
 	{"ctime",	time_ctime, METH_VARARGS, ctime_doc},
+#if defined(HAVE_TIMEGM) || (defined(HAVE_MKTIME) && defined(HAVE_WORKING_TZSET))
+    {"timegm", time_timegm, METH_O, timegm_doc},
+#endif
 #ifdef HAVE_MKTIME
 	{"mktime",	time_mktime, METH_O, mktime_doc},
 #endif
@@ -824,6 +867,7 @@
 clock() -- return CPU time since process start as a float\n\
 sleep() -- delay for a number of seconds given as a float\n\
 gmtime() -- convert seconds since Epoch to UTC tuple\n\
+timegm() - Convert a UTC tuple to seconds since the Epoch.\n\
 localtime() -- convert seconds since Epoch to local time tuple\n\
 asctime() -- convert time tuple to string\n\
 ctime() -- convert time in seconds to string\n\