April 6th - Oakland Critical Mass (every first friday)
6pm @ Frank Ogawa Plaza (12th St. BART entrance on Broadway & 14th St)

April 13th - Berkeley Critical Mass (every second friday)
6pm @ Downtown Berkley BART on Shattuck Ave

April 20th - Walnut Creek Critical Mass (every third friday)
6pm @ Walnut Creek BART

April 27th - San Francisco Critical Mass (every last friday)
6pm @ Justin Herman Plaza (near Embarcadero BART on Market St.)