You have a calendar. You have date of arrival and date of departure. You can do a spinner.
You can set the date of arrival dead easily, yes? The date of departure is a little trickier because you don't really want to set a default value of =Date()+1 because you actually want the default value to be one higher than the value you set for the arrival when you click on the calendar.
All you need to do is add a line of code to the standard calendar stuff.