Stage five, nine hour flight from Tokyo (Saturday afternoon) to San Francisco (Saturday morning again!), with bonus two-hour runway delay due to malfunctioning air conditioning. At least the delay reduces our four-hour layover in San Francisco to two hours. Stage six, five hour flight (with one-hour runway delay) from San Francisco (Saturday afternoon for the second time) to Boston (Saturday night). Stage seven, taxi ride home. Length of Longest Day: 37 clock hours, 30 traveling hours.