My reservation number is 2120411176, any my reservation confirmation was received on March 22 (corresponding to the last 4 digits, 1176) at 14:02:14. So, if I look at the first 6 digits, 212041, and parse them into three fields: 21, 20, and 41, and take each of these backwards, I get 12, 02, and 14. Now, I can believe that the confirmation was actually received by Smart at 14:02:12 and that it took a couple of seconds for the confirmation letter to get back to me. So, can I just interpret the first 6 digits as encoding the time in this backwards manner? I looked at some of the other confirmation numbers on the forum, and none of them seem to violate this kind of timing (no hours that are more than 24, no minutes or seconds more than 60).

So, my guess is:

ab cd ef ghij

is interpreted as fe hours, dc minutes, ba seconds on the date that comes from ghij.

Should be real easy to prove incorrect.