I saw one other post regarding the problem with February...because it's (usually) 28 days long, the DAYS of the week are the same if you accidentally switch to March. This is especially easy when booking online and doing it in a hurry.

The first time I managed this I was on Midway (RIP) from BOS-MCO. They could find no record of my reservation despite my holding a confirmation, and apparently neither they nor I could read cause they let me on the plane with no problem. Sometime on the trip I actually _read_ my itinerary a little more carefully and realized what I'd done--no getting out of it on the way back. Had to pay the fee.

I actually did this to a co-worker as well when booking his arrangements, but he/we noticed it immediately and changed it without a fee.

I always triplecheck these things, now. Have yet to get screwed up with international date line, time zones, and AM/PM, but I'm sure it's only a matter of time as my international travel increases, right?