Walmart Round Up Campaign Holiday Match When 12/01/2022 - 12/25/2022 12:00 am Add To Calendar Download ICS Google Calendar iCalendar Office 365 Outlook Live When shopping on Walmart.com or in the Walmart app, round up your purchase and donate to your favorite charity (CMN Hospitals). Walmart will match customer contributions 1:1 up to $1 million. The holiday match campaign ends Dec. 25.