I wasn't able to get an appointment in time so I just showed up on a Saturday morning before opening. There were a lot of people waiting outside but they had already posted a sign-in sheet on the outside and organized the onslaught of customers with skill and foresight.
Despite the crowd and being a walk-in I didn't wait much longer than an hour. When they had to take so much blood I started to faint I was laid down and supported with great care by the two ladies attending me.