Some plans are harder to replace than others, especially cruises, weddings, conferences, guided tours, timed-entry attractions and once-in-a-lifetime reservations. If one of these is the reason for your trip, avoid scheduling it too close to your arrival.
When possible, arrive at least one day early for anything you cannot easily reschedule. This gives you more room to handle flight delays, missed connections, jet lag or delayed baggage before the plans that matter most.
For other must-do activities, keep a simple backup option nearby. Weather, closures, strikes or sold-out time slots can affect even the best itinerary, so it helps to have a flexible alternative that does not require a reservation.
Helpful tip: For each major plan, write down one “Plan B” nearby, such as a café, museum, market, neighborhood walk or indoor attraction. That way, one change does not have to derail the whole day.