Hello @Valerie177,
That is possible if you use the rule-sets feature. You'll have to use Chrome or Microsoft's browser as it doesn't work with Firefox.
You have to first enable the rule-sets feature. Doing this will change the way your calendar is shown but you can still also see the full month view of the calendar by clicking on your listing name.
You then click on the first date on the calendar and choose to add a rule set for that date giving a discount if someone checks in on that date for 4 nights.
To enable the rule-sets feature:
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Go to the link below.
https://www.airbnb.com/hosttools
Ignore that it says that it's for professional hosts with multiple listings. I have just one listing and it works for me.
Scroll down to the "Work the way you want" section and click on the "Use the tools now" link. On the next page scroll to the "reservations" section and click on "Use the multi-calendar".
To create a discount rule for a four night stay:
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Log out and log in again and click on "Host" and then on "Calendar". You should now see the calendar dates all along in one line. Click on the name of your listing, beside the photo to see the full month view of your calendar.
Then click on the first date of the 4 you have free in July. In the box that appears on the right scroll down and click in the "Rule-sets" box. Select "Add rule-set". Then click "Customize" in the "Length of stay discounts" section. Click in the "Add a custom discount" box and select "4 nights". Then click in the "4-night discount" box and set your discount. Then click on "Save" at the end of the page. Remember to click on "Save" again in the box to the right of the calendar.
Now, if someone checks in for 4 nights on your first date they'll get a discount. They can still check in for one, two or 3 nights but they won't get the discount.
I've used this method to set discounts for a two night period that I have free in August and it works when I check it as a traveller.
Steve.
