Typically, there are a few Playdates each week. Two Public Playdates, and between two and 10 Private Playdates are scheduled.
Public Playdates go for one hour, and models are available for Private Playdates for around 3 hours at a time (some of that time, models will actually be in Private Playdates with other customers, so may not be available to you).
When there are no Playdates scheduled, you can choose to visit our friends at 17live.com. They run a much larger web-camming operation, with many models online and availbale all the time, but the overall style is different to Playdates.