def fromPattern(cls, datetime_string, datetime_pattern, time_zone, require_hour=True):

        '''
            a method for constructing labDT from a strptime pattern in a string
            https://docs.python.org/2/library/datetime.html#strftime-and-strptime-behavior
            iso_pattern: '%Y-%m-%dT%H:%M:%S.%f%z'
            human_friendly_pattern: '%A, %B %d, %Y %I:%M:%S.%f%p'
        :param datetime_string: string with date and time info
        :param datetime_pattern: string with python formatted pattern
        :param time_zone: string with timezone info
        :param require_hour: [optional] boolean to disable hour requirement
        :return: labDT object with datetime
        '''

    # validate inputs
        title = 'input for labDT.fromPattern'
        dT_req = [['%Y','%y'],['%b','%B','%m'],['%d'],['%H','%I']]
        req_counter = 0
        for i in dT_req:
            for j in i:
                if j in datetime_pattern:
                    req_counter += 1
        if not req_counter == 4 and require_hour:
            raise Exception('Datetime pattern %s must contain at least year, month, day and hour.' % title)
        try:
            get_tz = tz.gettz(time_zone)
        except:
            raise ValueError('Timezone %s is not a valid timezone format.' % title)

    # decipher datetime
        python_datetime = datetime.strptime(datetime_string, datetime_pattern)
        python_datetime = python_datetime.replace(tzinfo=tz.gettz(time_zone))
        dT = python_datetime.astimezone(pytz.utc)
        dt_kwargs = {
            'year': dT.year,
            'month': dT.month,
            'day': dT.day,
            'hour': dT.hour,
            'minute': dT.minute,
            'second': dT.second,
            'microsecond': dT.microsecond,
            'tzinfo': dT.tzinfo
        }
        return labDT(**dt_kwargs)