Prepare for emergencies
First Presbyterian Church of Concord hosts free concert featuring the Celts, 6 p.m. Sept. 23, 1965 Colfax St. Freewill offering. 925- 676-7177, www.fpcconcord.org.
Calling all astronomers
Mount Diablo Astronomical Society explores Stars of the Triangle, 6:30 p.m. Sept. 22, Mt. Diablo State Park lower Summit Road parking lot, Clayton. Bring binoculars, snacks, warm clothing. $10, parking free. 925-695-3134, www.mdas.net.
Ninth annual Oktoberfest elebration 11 a.m.-8 p.m. Oct. 6 (parade at noon); 11 a.m.-6 p.m. Oct. 7, downtown Clayton. Live music, German food, beer, wine, crafts, carnival, street performers. Free. www.claytonoktoberfest.com.
Contra Costa Chamber Orchestra presents "Seven Wonders of the World" with Jeremy Cohen, 7:30 p.m. Sept. 23, Lesher Center for the Arts, Walnut Creek, $10-$30 at door, 925-943-7469 or www.LesherArtsCenter.org.
Gently used books
Clayton Library book sale, members only 4-7 p.m., Oct 12; all others 10-6 p.m. Oct. 13; noon-4 p.m. Oct. 15, 6125 Clayton Road. 925- 672-3672, www.claytonlibrary.org.
Science and faith
Physicist Denny Lee speaks on science, faith 7:30 p.m. Sept. 29, Grace Chinese Alliance Church, 1630 Grant St. Concord. Child care available. 925-518-7272, http://gcac.us.
Lose a Lawn/Gain a Garden workshop 9 a.m.-1 p.m. Sept. 29, Contra Costa Water District, 1331 Concord Ave., Concord. Information on water-efficient landscaping. $20, with box lunch. 925-688-8033. Registration: http://www.gardenshf.org/adult-classes.html.
Diablo Valley Literacy Council seeks English language tutors. Training sessions: 9 a.m.-1 p.m. Sept 22, 29; 6:30-8:30 p.m. Sept. 25, 4000 Clayton Road, Concord. Must attend all sessions. Small fee for training materials. Information: http://dvlc.tripod.com, 925-685-3881.
St. Agnes fundraiser
Mention St. Agnes School on Oct. 3 when ordering at Yogurt Shack, Tavo's Pizza, Clayton Valley Center, 5434 Ygnacio Valley Road, and they will donate a portion of proceeds to school. Information: 925- 689-3990.
75th annual Walnut Festival Sept. 20-23, Heather Farm Park, 301. N. San Carlos Drive, Walnut Creek. Food, kids activities, rides, entertainment, more. $5. For times, information, www.thewalnutfestival.org/festival.php, 925-935-6766.
Youth Theatre Company presents "By the Kids, For the Kids," 5 p.m. Sept. 30, Shadelands Art Center, 111 N. Wiget Lane, Walnut Creek. Proceeds benefit Friends of Civic Arts Education scholarship fund, Monument Crisis Center. $10. 925-943-5846, www.youththeatrecompany.org.