Mira Jacob, The Sleepwalker's Guide to Dancing
George Musser of Scientific American, who wrote about his father-in-law's experience in the magazine's special edition on time, explained, "Officially there is no such time as '12 a.m.' Midnight is both the end of one day and the start of the next. In 24-hour time notation, it is both 2400 and 0000."
The fault for the mix-up lies with the airport, not the disappointed traveler. Flights should leave at 11:59 p.m. or 12:01 a.m. to avoid confusion. Some people, myself included, might even think of 12 a.m. as being noon, not midnight. Twelve o'clock, to my mind, completes the cycle. If it's 11:59 a.m., then it must be followed by 12 a.m., followed by 12:01 p.m. But I must be in the minority here, just as I was in thinking that the 21st century didn't begin until 2001, not 2000 when just about everybody else celebrated. Apparently they think the first century consisted of just 99 years. I think you must complete one cycle before starting the next, and the cycle ends at 12, not 11:59:59.
But Musser is right. Instead of speaking of 12 a.m. or 12 p.m., or 12 in the morning or 12 in the afternoon, as Mira Jacob does in her novel, The Sleepwalker's Guide to Dancing, we should speak of noon and midnight. That's what we always did when I worked for newspapers. Of course, there could always be confusion by someone as to whether it is midnight of the day just ending or of the day just beginning.