Experience Sikh and Punjabi culture with food and dance. For four hours Saturday, Somerville’s Union Square may as well be India, as Utsav! A Festival of Sikh and Punjabi Culture (“Utsav” is an Indian word meaning “feast day” or “festival”) takes over and provides a tour of Punjabi and Sikh culture and traditions, including homemade food, Bhangra dancing, performances of Gatka, a form of martial arts using swords and other weaponry, and performances by Dhandis, Sikh historical religious singers. The festival takes place from 4 to 8 p.m. Saturday at 90 Union Square.

Go Back 2 School with Geek Comedy Night. Salute the new school year with comedy inspired by “Revenge of The Nerds,” “Rock ’n’ Roll High School” and of course “Back to School” with host Kevin Harrington, headliner Ken Reid and Shawn Armistead, Thom Crowley, Wes Hazard, Elena Jawitz, Niki Luparelli, Amy Macabre, Dan Martin and Nick Ortolani (with special guest Wally Ramone). The $5 show runs from 8 to 10 p.m. Saturday Comicazi, 407 Highland Ave., Davis Square, Somerville.

Dance, dance, dance, dance. Explosive post-punk band Faux Ox releases its second album at 11 p.m. Saturday with help from three like-minded bands: garage-rock band Darling Pet Munkee as opener at 9 p.m. (said to be performing its last show of the year); dark, dramatic rock band Emily Peal and The Band of Skinny Men at 10 p.m.; and the baroque, angular, theatrical and experimental Bent Knee closing out the event at midnight. Tickets are $8 and the party is at Radio, 381 Somerville Ave., Union Square, Somerville.

Join the carnival. The 21st Annual Cambridge Carnival International Festival and Parade has arrived – well, when it arrives you’ll hear it. The Caribbean/African-themed carnival starts at 12:30 p.m. with a parade of dazzling handmade costumes accompanied by steel bands and percussion groups and settles into Kendall Square with DJs and bands playing Afro-Cuban, Brazilian, Caribbean, calypso, reggae, Kompa, Punta and salsa music. A variety of savory foods will be for sale, and there’s plenty for kids to do, including stilt-walking instruction from the OpenAir Circus from 1 to 4 p.m. and an interactive activity zone with story-telling, face painting, balloon art and arts and crafts activities – most free. The carnival, which has drawn crowds of up to 100,000 people, parties until 6:30 p.m. Sunday in Kendall Square.

The parade starts on River and Blackstone streets at Riverside Press Park near the Charles River, continues up River Street to Massachusetts Avenue and onto Main Street and ends at the carnival viewing stand, which is at Main and Albany streets.

Help T.T. the Bear’s Place celebrate its 40th. The Central Square rock club has entered its fourth decade, and the first night of its weeklong anniversary celebration is Sunday. The bands ushering in its new year are Permafrost (a reuniting of the brutally witty pop band fronted by Ad Frank), Sarah RabDAU and Self-Employed Assassins (the alternative piano pop band is also “coming out of hiding” for the show), indie singer-songwriter Eldridge Rodriguez and the progressive loud rock band Await Rescue (think “stadium-sized hooks and the songwriting sensibilities of Foo Fighters meet the aggression and raw energy of Every Time I Die”). Special guests are also promised, and the night benefits charities chosen by owner Bonney Bouley, including The Christopher Friedrich Memorial Fund, Songbird Sings, a domestic abuse support organization, and Sweet Paws Dog Rescue. Tickets are $10 for the night, running from 8:30 p.m. Sunday to 1:30 a.m. Monday at T.T. the Bear’s Place, 10 Brookline St., Central Square.