import calendar


def month_date_range(for_date_time):
    """
    Get a formatted date range string for the given date.

    Date range is aligned on the first day of the current
    month and ends on the first day of the next month from the
    specified date.

    Args:
        for_date_time (DateTime): The starting datetime object

    Returns:
        (String): "YYYYMMDD-YYYYMMDD", example: "19701101-19701201"

    """
    start_month = for_date_time.replace(day=1)
    _, num_days = calendar.monthrange(for_date_time.year, for_date_time.month)
    end_month = start_month.replace(day=num_days)
    timeformat = "%Y%m%d"
    return "{}-{}".format(start_month.strftime(timeformat), end_month.strftime(timeformat))