The half life of Aromasin is around 9 hours for males but since it is a suicidal inhibitor, the effects are prolonged which I'm sure Rick was referring to. Here is a quick run down:
-24 hours after one 25mg dose: estrogen levels are reduced by 70-80%
-72 hours after one 25mg dose: estrogen levels are still 40% below baseline (even though the drug itself is almost completely eliminated)
-120 hours after one 25mg dose: estrogen levels return to baseline (without rebounding)
So dosing can effectively be anywhere from ed to e3d and do it's job dependent on the individual's sensitivity. For the OP, it shouldn't make a difference for what time you take it in conjunction with dbol. I would just start at 12.5mg eod and adjust from there as needed.