Help! I can't rock out, with my clock out!

I need your help! Look at this:

One, two, one o'clock, three o'clock rock
Eight, six, three o'clock, two o'clock rock
Nine, seven, one o'clock, seven o'clock rock
We're gonna rock around the clock tonight

There's no way I can possibly rock to my maximum potential with a clock that's so obviously broken... What is causing the hours on my clock to be so messed up?

There are 24 hours in the day, so each of the times could be indicating one of two possibilities:
1/13, 2/14, 1/13, 3/15, 8/20, 6/18, 3/15, 2/14, 9/21, 7/19, 1/13, 7/19

If we substitute each of these numbers with its corresponding letter in the alphabet (1 - A, 2 - B, 3 - C, ... , 24 - X), we get: A/M, B/N, A/M, C/O, H/T, F/R, C/O, B/N, I/U, G/S, A/M, G/S If we choose the correct letter from each couple, we will get the word "ANACHRONISMS".