diff -r d801be922dc2 Lib/test/datetimetester.py
--- a/Lib/test/datetimetester.py	Mon Mar 18 10:59:41 2013 -0700
+++ b/Lib/test/datetimetester.py	Mon Mar 18 14:17:52 2013 -0700
@@ -619,6 +619,10 @@
         eq(td(hours=-.2/us_per_hour), td(0))
         eq(td(days=-.4/us_per_day, hours=-.2/us_per_hour), td(microseconds=-1))
 
+        # Test for a patch in Issue 8860
+        eq(td(microseconds=0.5), 0.5*td(microseconds=1.0))
+        eq(td(microseconds=0.5)//td.resolution, 0.5*td.resolution//td.resolution)
+
     def test_massive_normalization(self):
         td = timedelta(microseconds=-1)
         self.assertEqual((td.days, td.seconds, td.microseconds),
diff -r d801be922dc2 Modules/_datetimemodule.c
--- a/Modules/_datetimemodule.c	Mon Mar 18 10:59:41 2013 -0700
+++ b/Modules/_datetimemodule.c	Mon Mar 18 14:17:52 2013 -0700
@@ -2148,7 +2148,31 @@
     }
     if (leftover_us) {
         /* Round to nearest whole # of us, and add into x. */
-        PyObject *temp = PyLong_FromLong(round_to_long(leftover_us));
+        // PyObject *temp = PyLong_FromLong(round_to_long(leftover_us));
+        double whole_us = round(leftover_us);
+        int x_is_odd;
+        PyObject *temp;
+
+        whole_us = round(leftover_us);
+        if (fabs(whole_us - leftover_us) == 0.5) {
+            /* We're exactly halfway between two integers.  In order to do
+             * round-half-to-even, we must determine whether x is odd. */
+            temp = PyNumber_And(x, us_per_us);
+            if (temp == NULL) {
+                Py_DECREF(x);
+                goto Done;
+            }
+            x_is_odd = PyObject_IsTrue(temp);
+            Py_DECREF(temp);
+            if (x_is_odd == -1) {
+                Py_DECREF(x);
+                goto Done;
+            }
+            whole_us = 2.0 * round((leftover_us + x_is_odd) * 0.5) - x_is_odd;
+        }
+
+        temp = PyLong_FromLong(whole_us);
+
         if (temp == NULL) {
             Py_DECREF(x);
             goto Done;