def calculate_appointments(new_set, old_set):
    """
    Calculate different appointment types.  Used for making useful distinctions in the email message
    Ex1: Addition of HONEOYE
    new_set = {'LIVERPOOL', 'BROOKLYN', 'HONEOYE', 'KINGSTON'}
    old_set = {'LIVERPOOL', 'BROOKLYN', 'KINGSTON'}
    returns ->->
    new_appointments = {'HONEOYE'}
    old_appointments = {'LIVERPOOL', 'BROOKLYN', 'KINGSTON'}

    Ex2: No Changes
    new_set = {'LIVERPOOL', 'BROOKLYN', 'HONEOYE', 'KINGSTON'}
    old_set = {'LIVERPOOL', 'BROOKLYN', 'HONEOYE', 'KINGSTON'}
    returns ->->
    new_appointments = set() (empty set)
    old_appointments = {'LIVERPOOL', 'BROOKLYN', 'HONEOYE', 'KINGSTON'}

    """

    new_appointments = new_set.difference(old_set)  # New minus Old
    old_appointments = new_set.intersection(old_set)  # New ∩ Old
    return new_appointments, old_appointments  # Return resulting sets