Sesshins, periods of intensive zazen held in silence and seclusion, are offered about once a month at the Rochester Zen Center, and vary in length from two to seven days. About ten hours of formal zazen is done each day, and more hours of informal zazen are encouraged. Dokusan is offered three times a day. As sesshins are rigorous, demanding a great deal of the sitter, it is advisable to be sitting regularly at home (and at a Center if possible) before applying to sesshin. Anyone who has been to an introductory workshop at the Rochester Zen Center or an affiliate may apply. It is also generally advisable for beginners to start with a 2- or 4-day sesshin.