If you’ve ever been stuck on a delayed flight and wondered what triggered the holdup, one of the biggest factors may be surprisingly simple: your departure time.
Travel expert Ferdinando D’Agostino says there is one part of the day passengers should try to avoid if arriving on schedule is a priority: the stretch from 4pm to 8pm.
The reason is that disruption tends to build as the day goes on.
A minor issue affecting an early departure may cause little trouble on its own, but by late afternoon and evening, repeated delays can stack up and ripple through the airport. By then, the impact is often being felt not only on the runway, but also at security and in packed departure areas.
“For any day of the week, the earlier the flight, the easier it will be,” D’Agostino, from airport transfer company Transfeero, explained, adding that many travelers avoid the crack-of-dawn slots simply because they don’t fancy waking up in the middle of the night.
That hesitation may be working against them, since early departures ‘have much less chance of being delayed by an issue with the flight before’.
Timing is only part of the equation, though. The day you travel can also have a major effect on how smoothly your trip goes.
D’Agostino pointed out that Monday mornings are ‘often busy with business travelers, especially on routes between major cities like London to New York’.
“Airports are usually busiest before 9am, and tend to be quieter later in the day, when peak business flights have departed, and the airport is less full of tourists,” he said.
Because of that, he suggested that Monday evenings can still be a smart option, even though later flights are generally more exposed to knock-on disruption.
Saturday mornings are another period that tends to get crowded.
D’Agostino explained: “The morning is the busiest time to travel on a Saturday, with airports often being full of leisure passengers who have chosen early morning flights that are often the cheapest. This means that check-in desks and security can have long waiting times, but this eases in the afternoon. Much like Mondays, evenings are generally the best time to travel on a Saturday, to avoid the crowds of the morning.”
Even so, Saturday does not take the top spot for overall airport pressure.
In Europe, Friday is typically the most congested day. Leisure travelers often book afternoon or evening departures to maximize their break without using an extra day off, while business passengers are also heading home at the same time.
D’Agostino said the outcome is airports and security queues left ‘under pressure for the whole weekend.’
Sunday can be just as challenging in many places, especially later in the day, as people return from trips before the work week begins. D’Agostino said this is particularly clear in popular short-break destinations such as Rome.
In the US, the pattern changes slightly. Along with Friday and Sunday, Thursday is also one of the busiest days for both domestic and international travel.
Much of that traffic is driven by long-weekend travel. According to D’Agostino, many UK passengers flying to cities such as New York choose Thursday evening departures so they can arrive early on Friday and make the most of their time away. He said that tendency has made Thursdays ‘just as vulnerable to delays as weekends.’
That fits with the way U.S. aviation data is presented by the Department of Transportation’s Bureau of Transportation Statistics, which tracks on-time performance by month and also breaks results out by time of day. Its latest national figures show that in May 2026, 77.78 percent of flights arrived on time, while 0.94 percent were canceled and 0.29 percent were diverted.
For travelers who have some flexibility, the quieter choice is usually midweek.
Tuesday and Wednesday generally see lower demand, which means fewer crowds and gives airlines more chance to recover from delays that built up over the weekend.
Overall, the simplest strategy is clear: book early in the day, aim for the middle of the week, and avoid the late-afternoon to early-evening window whenever possible.