--- conversion.py	2014-02-11 22:37:15.000000000 +0100
+++ conversion.py.patched	2014-04-28 19:53:51.609247000 +0200
@@ -260,14 +260,28 @@
 
         Returns a bytes.
         """
-        (hours, remainder) = divmod(value.seconds, 3600)
+        return_format = '{:02d}:{:02d}:{:02d}'
+        msc = value.microseconds
+        total_sec = abs(value.days * 86400 + value.seconds) # abs() is important!
+
+        if msc:
+            return_format = return_format + '.{:06d}'
+            if value.days < 0:
+                msc = 1000000 - msc
+                total_sec -= 1
+
+        (hours, remainder) = divmod(total_sec, 3600)   # divmod with total_sec < 0 is terrible!
         (mins, secs) = divmod(remainder, 60)
-        hours = hours + (value.days * 24)
+
+        if value.days < 0:
+            return_format = '-' + return_format
+
         if value.microseconds:
-            return '{:02d}:{:02d}:{:02d}.{:06d}'.format(
-                hours, mins, secs, value.microseconds).encode('ascii')
-        return '{:02d}:{:02d}:{:02d}'.format(
-            hours, mins, secs).encode('ascii')
+            return return_format.format(
+                hours, mins, secs, msc).encode('ascii')
+        else:
+            return return_format.format(
+                hours, mins, secs).encode('ascii')
 
     def _decimal_to_mysql(self, value):
         """
@@ -369,7 +383,7 @@
 
     def _TIME_to_python(self, value, dsc=None):  # pylint: disable=C0103
         """
-        Returns TIME column type as datetime.time type.
+        Returns TIME column type as datetime.timedelta type.
         """
         time_val = None
         try:
@@ -380,6 +394,8 @@
             mcs = 0
         try:
             (hrs, mins, sec) = [int(i) for i in hms.split(b':')]
+            if value[0] == b'-'[0]: # important 
+                mins, sec, mcs = -mins, -sec, -mcs
             time_val = datetime.timedelta(hours=hrs, minutes=mins, seconds=sec,
                                     microseconds=mcs)
         except ValueError: