method casts given timeperiod accordingly to time qualifier.
    For example, will cast session time format of 20100101193412 to 2010010119 with QUALIFIER_HOURLY

def cast_to_time_qualifier(time_qualifier, timeperiod):
    """ method casts given timeperiod accordingly to time qualifier.
    For example, will cast session time format of 20100101193412 to 2010010119 with QUALIFIER_HOURLY """

    if time_qualifier == QUALIFIER_HOURLY:
        date_format = SYNERGY_HOURLY_PATTERN
    elif time_qualifier == QUALIFIER_DAILY:
        date_format = SYNERGY_DAILY_PATTERN
    elif time_qualifier == QUALIFIER_MONTHLY:
        date_format = SYNERGY_MONTHLY_PATTERN
    elif time_qualifier == QUALIFIER_YEARLY:
        date_format = SYNERGY_YEARLY_PATTERN
    else:
        raise ValueError('unknown time qualifier: {0}'.format(time_qualifier))

    pattern = define_pattern(timeperiod)
    t = datetime.strptime(timeperiod, pattern)
    return t.strftime(date_format)