Because ticket prices can vary widely, it is good to search for tickets several times and at different times. The best day to find and book cheap flights is usually Tuesday. It is often cheaper to book your plane ticket well before you go on vacation. For distant destinations, the cheapest flight tickets are often those booked 4-5 months in advance. Sometimes it is cheaper to book last minute. Wednesdays are generally the cheapest day to fly. In addition, there are more cheap flights early in the morning than later in the day.