Why can I only book a room for 30 minutes?
Answer
You can actually book a room for up to three hours, and have two active bookings at any given time.
Here's what you may have done wrong: when you click on a little 30 minute block on the booking grid, you need to scroll to the bottom of the page to select the end time for your booking. After you make your selection, you'll then see that the grid has updated to include the remaining 30 minute blocks of your desired time. Then just click the "Submit Times" button below.
Check out how I just booked room 302 for two and a half hours in the screencaps below:
That's all there is to it!