1step,rule,n_before,n_after,n_removed,rationale21,month >= 1992-03-01 (training start per spec),417,415,2,rows 1992-01/02 lack full lag/neworder features; spec starts at 1992-0332,s+1 <= last origin 2026-08-01 (target observed at origin),415,413,2,rows dated after 2026-07 have targets after the last origin (information rule)4