Midweek travel (especially Tuesdays and Wednesdays) is less busy and likely cheaper than flying on weekends. The most affordable days to fly on United Air Lines are Tuesdays and Wednesdays. Demand is generally lower these days, which often results in reduced fares. For more information, you can call 1-888-415-1531(Live Person) or {+1-888-415-1531} (Quick Connect).