I can't speak for AC
specifically, but from my experience, Sunday night and Monday morning are generally the busiest, due to the high frequency of business travelers commuting to and from work. On the flip side, Sunday mornings and Monday evenings are usually not too bad. If you choose to try Sunday morning or Monday evening, you should not have too much trouble.
Hope this helps!
9E, AA, AQ, AX, BA, CO, CP, DH, DL, EV, F9, FL, HA, HP, KL, NK, NW, OH, OO, QX, RP, RW, S5, TW, UA, US, WN, YV, ZK, ZW