I checked our Internal documentation, and did not find anything that is specific about this. I also tried doing it myself in the 8.1 GUI, but got some funky error message that I need to work out after I review the documentation
However, I did notice a 'Delete' button in the lower right corner, which implies that you can pick on a desired date, and Delete it from the schedule
I was also able to do this from the normal scheduler interface by right-clicking on a Date, and picking Delete
It does not look like there is a way to set it up this way other than choosing the dates individually