Own vehicle track days typically run in 2 formats, open pitlane and groups (sessions).
A track day with groups, or sessions, is where vehicles will be split into 3 or 4 groups, with each group getting 15 or 20 minutes of track time per hour. Generally, the hourly time slots given to each group will remain the same throughout the day. For example, if your group goes out at 09:00-09:20, your next session will be at 10:00-10:20 and so on. Track days with groups will appear on our track day calendar with the format stating '3 Groups P/H', or '4 Groups P/H'.
Open pitlane means you can come and go as you please, in and out as many times as you like, and for as long or short as you like. Although only a certain number of vehicles are allowed on the track at any one times, so if the track is 'full' you may have to queue and wait for someone to come in before you can go out.