def METHOD_NAME(self) -> str:
    """
    Returns a string representation of the timerange as used by parse_timerange.
    Follows the format yyyymmdd-yyyymmdd - leaving out the parts that are not set.
    """
    start = ''
    stop = ''
    if startdt := self.startdt:
        start = startdt.strftime('%Y%m%d')
    if stopdt := self.stopdt:
        stop = stopdt.strftime('%Y%m%d')
    return f"{start}-{stop}"