When Does Your Yoga Class Begin?

When does class begin? Is it when you walk into the yoga room, choose your space, place your mat, stretch out on the floor, and close your eyes? Is it when the teacher says, "Come to standing position?" Is it when your mind starts clearing from the obstacles of the day and the first drop of sweat falls from your brow? There are numerous cues and clues to when class begins, but ultimately it is up to you.
"When does class begin?" Is an important question. It is not just the scheduled time. After all, most people don't show up knowing what to expect and they miss having the best possible experience. Yoga is a highly personal experience and one that everyone needs to try. I have been in a yoga class for 3 years now. I am very flexible and attribute this to yoga.