We always fly in a day early. We have an abysmal track record with transatlantic flights getting there on time, and have been delayed at least 24 hours before. Another thing to consider - my friends had their luggage lost on our last trip to France. The airline found his and he had it the next day. Hers never showed. An extra day just gives it time to get there. I also have a really hard time with jet lag, so one extra day means I'm not quite a zombie when the tour starts.