Day passes—and all pass types—are decided by your local transit agency.
If you're using the Umo App, you can see what passes your local transit agency by going to Wallet > Buy > Add Pass > select pass > Purchase.
If you're using a Umo Card, you can purchase a pass at the Umo Passenger Portal (umopass.com for U.S. riders, and ca.umopass.com for non-U.S. riders) by going to My Wallet > Buy Value or a Pass > Passes > Choose a Pass.
Please contact your contact your local transit agency for further details on available passes and other fare-related offerings.