Guest NPS — one definition, and what the window does to it
Same formula everywhere (promoters 5★ − detractors 1–3★, ≥5 reviews, whole number). The only thing that differs across the code is the window. The canonical is 180 days. 90d is what the team-app Values/score uses today — the diluting window. Find the column that matches the number you report in the weekly meeting.
Reading it — if 180d reproduces your reported figure and 90d is lower, that confirms the window (not the maths) was diluting it. Once you're happy, Phase 3 sets every surface to the canonical window and the number is identical everywhere.