convert/mtn: mtn does not record timezones, mark dates as UTC (issue1624)

hgext/convert/monotone.py

@@ -107,7 +107,8 b' class monotone_source(converter_source, '
                 value = value.replace(r'\\', '\\')
                 certs[name] = value
         # Monotone may have subsecond dates: 2005-02-05T09:39:12.364306
-        certs["date"] = certs["date"].split('.')[0]
+        # and all times are stored in UTC
+        certs["date"] = certs["date"].split('.')[0] + " UTC"
         return certs
 
     # implement the converter_source interface: