If you want to block off some times on the Calendar screen for dentist appointments, meetings, etc., all you need to do is click on the time slot you want to block off, click "Block Time,"
You can then click on the blocked time slot and add a reason/description. You can also put your cursor on the blocked time slot and then drag out the time slot with the handle on the bottom of the time slot.
These blocked time slots will not show up on the Route->Process page.