We have changed how we collect and accept calendar information. Readers must now submit all items through our website. Go to events.contracostatimes.com. Click on "submit your event." You'll have to register at this point, and enter your event, but you don't have to pay. Submitting your event in this way will ensure it is part of our easily searchable online database as well as a candidate for space in our publications.

Creek Crew Work Day. Grab your gardening gloves, work clothes and shoes, water and snacks, and spend a day -- rain or shine -- cleaning up Arroyo Viejo Creek. Adult chaperon required. 9 a.m. to noon. March 15. Meet at Oakland Zoo, 9777 Golf Link Road, Oakland. Registration requested. 510-632-9525, ext. 209, Chantal@oaklandzoo.org.

Arbor Day Tree Planting. Come out and plant a tree at Urban Releaf's Arbor Day tree planting. 10 a.m. March 15. Meet at Wo'se Community Church, 8924 Holly St., Oakland. 510-601-9062, urbanreleaf.org.

Oakland Tech Fundraiser. Oakland Tech PTSA holds their annual "This Is It," auction and fundraiser featuring silent and live auctions, hearty appetizers, fun, community and entertainment. 6 to 10:30 p.m. March 15. Uptown Body and Fender, 401 26th St., Oakland. $35. oaklandtech.com

Jazz at the Chimes. Grupo Falso Boianao perform their blend of traditional Brazilian choro music with modern influences of jazz, flamenco and samba. 2 p.m. March 16. Chapel of the Chimes, 4499 Piedmont Ave., Oakland. $10-$15. 510-654-0123, www.jazzatthechimes.com

Oakland Civic Orchestra. Now in its 22nd year, the Oakland Civic Orchestra continues its tradition of providing free classical music to the community with "Eastern Confluence," with Artistic Director Martha Stoddard and Assistant Conductor Jason Oestenstad. 4 p.m. March 16. Lake Merritt United Methodist Church, 1330 Lakeshore Ave., Oakland. Free. 510-597-5027.

Library Branch Talk. Discover the interesting history of the Montclair Branch of the Oakland library system at a talk with Dorothy Lazard and Kathleen DiGiovanni of the Oakland History Room. 6 p.m. March 18. Montclair Branch, Oakland Public Library, 1687 Mountain Blvd., Oakland. 510-482-7810, oaklandlibrary.org.

Red Cross Volunteer Orientation. American Red Cross Northern California Region holds a volunteer orientation for anyone interested in working with blood donors, deliver blood, or help with special projects. Sign-up required. 3:30 p.m. March 20. Oakland Blood Donation Center, 6230 Claremont Ave., Oakland. 510-594-5165, anne.blackstone@redcross.org.

Fundraiser Brunch. Burbank Preschool Center's first fundraiser brunch features brunch, beverages, music, raffle and more. Adults only. 11 a.m. to 1:30 p.m. March 23. Piedmont Community Hall, 711 Highland Ave., Oakland. $40. 510-729-7771, www.eventbrite.com.

Free Computer Tutoring. Brush up on your computer basics at free computer tutoring. 1 to 3 p.m. Saturdays. 4 to 6 p.m. Tuesdays. Rockridge Branch Library. 5366 College Ave., Oakland. 510-597-5017, www.oaklandlibrary.org.

Peralta Hacienda Kids Club. Kids from 5 to 15 can play and experience Oakland's original rancho through traditional arts and hands-on activities: Make adobe bricks and corn husk dolls, learn about native plants and make seed balls, traipse through the creek area and participate in other nature-based tours. 2:30 to 5 p.m. Saturdays. Peralta Hacienda Historical Park, 2465 34th Ave., Oakland. Free. 510-532-9142, www.peraltahacienda.org.