How do I avoid leaving one day openings when I allow guests to use instant book?

[Sylvia5]

I recently had a guest use instant book and it left one day open between his trip and the next guest. This night will go I rented as we have a four night minimum.  How can I avoid this in the future?  Our summer rates are very high and we typically book every day of the summer so I ant to avoid this going forward.  Thank you for your suggestions.  I know I could offer this one night but with the high  rate, cleaning fee, late check in and early check out time due to the extensive time that housekeeping requires I know no one will book just one night. 

[Mike77]

4 night minimum is what is causing the gaps.  4 does not go into 30 equally.  Mathamatically you will always have gaps.

Mike

[Deborah1]

the only thing I can think of is 7 day rental with a certain day for check ins. I think I saw a way to do this when I was setting up by listing.