Framing the stats — rolling, period & snapshot windows
Every ranking signal is measured over a time window.
Before ranking can score a product, it has to decide which slice of time to measure — the window. Every signal (best-selling, trending, CTR…) is computed over this window, and the mode you pick changes which orders and events count. There are three modes, set on a collection’s Setup tab under Use sales from.
1. Rolling — a window that slides with the clock
Rolling always ends at now and reaches back N hours or days. Because “now” moves, the whole window slides forward continuously — an order from 8 days ago that counted yesterday quietly drops out today. It’s the freshest possible view, ideal for fast-moving catalogs where you want the ranking to reflect the last few days at all times.
2. Period — the last completed calendar unit
Period measures a completed calendar unit — e.g. last week (Mon–Sun) or last month. The current, still-open week doesn’t count yet, so the window holds perfectly steady all week, then jumps forward the moment the week turns. It’s stable and comparable period-to-period — good for weekly or monthly reporting cadences.
3. Snapshot — a frozen date range
Snapshot pins the window to an exact date range and freezes it. The same orders count forever — nothing rolls in or out — until you edit the range. Reach for it when the period itself is the point: a launch week, a holiday sale, or a seasonal capsule you want ranked by how it performed then, not now.