Only options right now: Offer a discount from 7 nights or one month. Maybe provide more customizability.
One potential feature: Setting discounts based on the number of nights booked (5% for two nights, 10% for 3 nights, etc.)
Also custom long-term discounts by specific month (30% off in January, 10% off in June, etc.)
Also, possibly add the functionality for long-term stay rate increases instead of just discounts from normal rates.