Yes, flight times, from the scheduled departure to the flight number, can change post-booking. This is especially common during high air traffic seasons or in the aftermath of significant disruptions, such as a pandemic. During the COVID-19 pandemic, for instance, a lot of flights were canceled because of coronavirus.

Airlines reschedule flights for a variety of operational and safety reasons, often to avoid total cancellations. The most common cause is weather-related disruptions; if a storm is forecasted, an airline may shift a morning flight to the afternoon to ensure safe takeoff conditions. Technical issues and maintenance are also major factors; if an aircraft develops a minor fault, the airline might push the schedule back to allow engineers time for repairs rather than grounding the plane entirely. Additionally, crew duty time limits are strictly regulated by aviation authorities; if a pilot or cabin crew member reaches their maximum legal working hours due to previous delays, the flight must be rescheduled to wait for a fresh crew. Finally, airlines may adjust schedules for network optimization, such as consolidating two half-empty flights into one larger service or managing "airport congestion" during peak travel periods to comply with strict air traffic control slots.