Click on the date you and the other side are available. That will bring up a calendar feature. If the date is unavailable it will be blocked out and you can click on another date that is open.
To see available dates for a month, first select a 4 or 8 hour time slot and then the current month’s calendar will appear with available times in dark gray. If you want to check the next month, simply click on the right arrow up in the line where the month appears.