code: def unixtime_to_datetime(ut):
      
  
      dt = datetime.datetime.utcfromtimestamp(ut)
      dt = dt.replace(tzinfo=tz.tzutc())
      return dt
docs: Convert a unixtime timestamp to a datetime object.
      The function converts a timestamp in Unix format to a
      datetime object. UTC timezone will also be set.
      :param ut: Unix timestamp to convert
      :returns: a datetime object
      :raises InvalidDateError: when the given timestamp cannot be
          converted into a valid date