          "Seconds; i.e. '00' to '59'"
          return '%02d' % self.data.second
  
      def u(self):
          "Microseconds"
          return self.data.microsecond
  
  
  class DateFormat(TimeFormat):
      year_days = [None, 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334]
  
 
</s> remove u                 Microseconds.                             ``0`` to ``999999``
 </s> add u                 Microseconds.                             ``000000`` to ``999999``
        "Microseconds; i.e. '000000' to '999999'"
        return '%06d' %self.data.microsecond
          "Seconds; i.e. '00' to '59'"
          return '%02d' % self.data.second
  
      def u(self):
        "Microseconds; i.e. '000000' to '999999'"
        return '%06d' %self.data.microsecond
        "Microseconds; i.e. '000000' to '999999'"
        return '%06d' %self.data.microsecond
  
  
  class DateFormat(TimeFormat):
      year_days = [None, 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334]
  
keep keep keep keep replace replace keep keep keep keep keep
 Fixed #18951 -- Formatting of microseconds.

Thanks olofom at gmail com for the report. 
django/utils/dateformat.py