1step,rule,n_before,n_after,n_removed,rationale21,month < 1992-03-01 (before training start; ip lags / neworder_chg incomplete),417,415,2,Task specifies training rows start at s=1992-03-01; neworder_chg missing for 1992-01/0232,s + 1 > last origin 2026-08-01 (target not available at last origin),415,413,2,Information rule: label y_{s+1} must be dated <= origin t4