The United same day change policy is incredibly lenient by the standards of travel. The following information is essential:
The flight must be managed and promoted by UA. The restriction only applies to award tickets; basic economy rates, specific bulk, group, or consolidator tickets are not included. Starting 24 hours prior to your scheduled departure, you may ask for a same-day change. If the new one does and it does so within 24 hours of the time your request is made, you may switch to a ticket that departs the day before or the day following your initial trip. Although airports for the origin and destination may change, links may be added or removed. If you check bags, you can change your flight the same day if you do it at least 60 minutes before the start of your new journey.
