Thanks so much for your help and advice!

Two questions from last night: 1) When you say AR(12) you mean as in 12 lag coefficients, not as in a single seasonal lag coefficient, right? And 2) When your AUTOBOX software says "pulse" is that the same as X12's additive outlier (AO) -- a single month -- or is it more like X12's temporary change (TC) which affects several months?