There really isn't a way to do that. You can say that you only accept check ins on Thursdays, for example, but that would be in effect every week, and I assume you only want it for one specific weekend.
If for a specific weekend, you only want a four day booking, as you've given an example of above, you could set a four-day minimum on those specific dates.
You could also consider getting a frend or co-host to do the key exchange, or setting up self-check in with a lockbox or keypad: then you wouldn't have to be there.