In 2026, the standard policy for most airline-operated and "Priority Pass" lounges is that you can enter 3 hours before your scheduled departure time. This rule is strictly enforced at busy hubs like Heathrow, Changi, and Dubai to prevent overcrowding and ensure that departing passengers have a place to sit. However, if you are a Business or First Class passenger on a connecting flight, you generally have unlimited access to the lounge during your layover, even if it exceeds 3 hours. Some "Paid" lounges like Plaza Premium or Centurion may allow you to purchase extra hours if you arrive early. It is a "pro-tip" for 2026 to check if your lounge has a "Late Arrival" clause; if your flight is delayed, they will usually allow you to stay until your new boarding time, provided the lounge hasn't reached its legal fire-code capacity. Always have your digital boarding pass ready, as it is your "key" to the 3-hour window.