 What time should you leave for the airport? With the FAA reporting record numbers of flights, it begs the question, how early is too early? Or how late is too late to show up for check-in? Airlines generally recommend two hours for domestic departures and three for international flights. But travel experts tell the Wall Street Journal people with carry-on bags only can shave off about 30 minutes. Same if you download your boarding pass ahead of time. Subtract 20 minutes for TSA pre-check.