Napa Earth Day Activities 11:00 a.m. – 4:00 p.m.: Come by the Oxbow Commons Park behind the Oxbow Market from 11:00 – 4:00 p.m. and visit the all of the tabling activities and venders that contribute to Earth Day. Stop by the Napa Solano Audubon’s table and learn all about our many programs. There will be food and activities for all ages.