Some tickets can be purchased in advance, while others can be used for same-day travel only. This is referred to as the ticket validity period, and it depends on the type of ticket and your transit agency's policies.
You can view information about a specific ticket type before purchasing it by tapping on the information icon next to its name on the Select Ticket screen.
Information icons for each fare type
You can also refer to FAQs located in the Help section of the app.
If you've already purchased the ticket, tap the Ticket Info button located at the bottom of the ticket. The Ticket Info tab will show the ticket validity period. Tap T&Cs to view ticket terms and conditions.