from datetime import datetime


def in_date_set(date_set, check_date):
    """Checks whether check_date is within any of the bounds in date_set"""
    check_month = datetime(year=check_date.year, month=check_date.month, day=1).date()
    for pair in date_set:
        p0 = datetime.strptime(pair[0], '%Y-%m-%d').date()
        p1 = datetime.strptime(pair[1], '%Y-%m-%d').date()
        if p0 <= check_month <= p1:
            return True
    return False