Transatlantic flights, particularly those flying Eastward (e.g., NYC to London), fly at night for three primary reasons: wind assistance, airport scheduling, and business efficiency. Eastward flights utilize the Jet Stream, powerful high-altitude winds that can push a plane at speeds exceeding 600 mph, shortening the trip to about 6-7 hours. By leaving at 8:00 PM and arriving at 8:00 AM, the airline hits the "Morning Bank" of arrivals, allowing business travelers to start their day immediately and providing seamless connections to further European destinations. Conversely, Westward flights (London to NYC) are usually daytime flights to fight the Jet Stream and avoid "red-eye" fatigue in the opposite direction. Additionally, many European airports like Heathrow have strict night curfews that prohibit loud takeoffs between 11:30 PM and 6:00 AM, so airlines must time their ocean crossings to land exactly as the "gates open" in the morning to maximize the number of daily flights an aircraft can perform.