By now you've probably figured this out, but if not: If you're on a computer, not a phone, click and release on any day in the range you want to block. On the left/right sides of that day you should now see a small round "button" with three small vertical lines. Drag either or both sides to cover the range of dates you want to block, make available, or set to a new price. If you're using the iPhone app, it works differently, and is semi-broken. (For example, you can only block, not unblock.) Instead of click-and-drag, just touch each date in your range with your finger. As you touch each date, it'll turn into a dark circle, and each previously touched date will remain dark. When ytou've got all the days you want selected, click the "Block" button at the bottom, or click the price field to reset the prices.
