Celebrate National Burger Day and Memorial Day this weekend in Northwest Austin.

Thursday

Donation night Whataburger is partnering with the Round Rock Express to support Town and Country Sports, an athletic facility serving youths in Northwest Austin. From 5-8 p.m., 20 percent of proceeds at the RM 620 location are donated to the organization to go toward supporting youth-oriented community activities and sportsmanship programs. A “Whataburger for a Year” raffle and a special guest appearance from Whataburger’s mascot, Whataguy, are also included. 5-8 p.m. 13201 N. RM 620. 512-249-5202. www.whataburger.com

Saturday and Sunday

World War II re-enactments Camp Mabry is hosting its semiannual World War II re-enactments this Saturday and Sunday. The re-enactments will focus on the history of the 36th Infantry Division of the Texas Army National Guard during WWII. The free two-day event will also provide visitors the opportunity to witness firing demonstrations of U.S. and German small arms of WWII. 11 a.m. and 2 p.m. (Sat. and Sun.). Camp Mabry, 2200 W. 35th St. 512-782-5770. https://tmd.texas.gov/museum

Sunday

National Burger Day Celebrate National Hamburger Day by getting a free burger. On Sunday the first 10,000 people to sign up for Postmates—a delivery app—will get a free burger from one of the participating local restaurants. Sign up here. In Northwest Austin, try a burger at Oasthouse Kitchen + Bar, Scoreboard Sports Bar & Grill, P. Terry’s Burger Stand or at Domain Northside.

Monday

Cap Tex Triathlon The event begins with a swim in Lady Bird Lake. Cyclists then head north to the Texas Capitol. The run course loops through Butler Park and the Palmer Events Center before the finish and post-race party at Auditorium Shores. 6:45 a.m. (race start). $165 (individual, preregistration), $175 (individual, on-site), $225 (relay, preregistration), $235 (relay, on-site). Various locations in downtown Austin. www.captextri.com All-day happy hour Z’Tejas is celebrating the holiday with happy hour specials all day, including margaritas and mules for $6-$7. The Arboretum location offers an expansive outdoor patio overlooking Loop 360. 10 a.m.-10 p.m. Z’Tejas, 9400-A Arboretum Blvd. 512-346-3506. www.ztejas.com