Spirit Airlines Flight Change Policy allows passengers to make changes to their flight for a fee, depending on the ticket type and when the change is made. Changes can be made up to 24 hours before departure, with higher fees for last-minute changes. If a change is made within 24 hours of booking, there is no fee. Fare differences may also apply. Spirit’s policy provides flexibility, but all changes are subject to availability and terms based on the original booking.
https://www.toursntravelpro.com/flight-change-policy/spirit-airlines-flight-change-policy/