From 70c1ef0f273721b9f7601e230b472fc04a479286 Mon Sep 17 00:00:00 2001
From: Satya Patel <satyapatel111@gmail.com>
Date: Tue, 23 Dec 2025 13:00:23 -0500
Subject: [PATCH] fix(analytics): use rolling 7-day window for WAU calculation
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Previously WAU was calculated using non-overlapping weekly buckets.
Now it uses a proper rolling 7-day window for each day, showing how
WAU changes day-over-day.

Definition: Users with workspace_created events on 3+ distinct days
within the rolling 7-day window ending on each report date.

Also updates WAUTrendChart to use 'date' field instead of 'week'.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
---
 .../WAUTrendChart/WAUTrendChart.tsx           |  4 +-
 .../trpc/src/router/analytics/analytics.ts    | 74 +++++++++++--------
 2 files changed, 47 insertions(+), 31 deletions(-)

diff --git a/apps/admin/src/app/(dashboard)/components/WAUTrendChart/WAUTrendChart.tsx b/apps/admin/src/app/(dashboard)/components/WAUTrendChart/WAUTrendChart.tsx
index 40557cbc0a5..1dc7f334542 100644
--- a/apps/admin/src/app/(dashboard)/components/WAUTrendChart/WAUTrendChart.tsx
+++ b/apps/admin/src/app/(dashboard)/components/WAUTrendChart/WAUTrendChart.tsx
@@ -18,7 +18,7 @@ import type { ReactNode } from "react";
 import { Area, AreaChart, XAxis, YAxis } from "recharts";
 
 interface WAUData {
-	week: string;
+	date: string;
 	count: number;
 }
 
@@ -74,7 +74,7 @@ export function WAUTrendChart({
 					<ChartContainer config={chartConfig} className="h-[200px] w-full">
 						<AreaChart data={data} margin={{ left: 0, right: 0 }}>
 							<XAxis
-								dataKey="week"
+								dataKey="date"
 								tickLine={false}
 								axisLine={false}
 								tickFormatter={(v) =>
diff --git a/packages/trpc/src/router/analytics/analytics.ts b/packages/trpc/src/router/analytics/analytics.ts
index a633bdc73cd..3eea1445442 100644
--- a/packages/trpc/src/router/analytics/analytics.ts
+++ b/packages/trpc/src/router/analytics/analytics.ts
@@ -105,41 +105,57 @@ export const analyticsRouter = {
 		)
 		.query(async ({ input }) => {
 			const days = input?.days ?? 30;
-			const numWeeks = Math.ceil(days / 7);
+			const lookbackDays = days + 7; // Extra 7 days to cover rolling windows
 
-			// Calculate WAU for each week
-			const weeklyData: { week: string; count: number }[] = [];
-
-			for (let i = numWeeks - 1; i >= 0; i--) {
-				const weekEnd = i * 7;
-				const weekStart = weekEnd + 7;
-
-				// Only count workspace_created as meaningful product usage
-				const { results } = await executeHogQLQuery<[[number]]>(`
-					SELECT count(DISTINCT person_id) as wau_users
+			// Rolling 7-day WAU: for each day, count users with 3+ active days
+			// of workspace_created events in the preceding 7-day window
+			const { results } = await executeHogQLQuery<[string, number][]>(`
+				SELECT
+					report_date as date,
+					count(DISTINCT person_id) as wau
+				FROM (
+					SELECT
+						report_date,
+						person_id,
+						count(DISTINCT activity_date) as active_days
 					FROM (
-						SELECT person_id, count(DISTINCT toDate(timestamp)) as active_days
+						SELECT toDate(now()) - number as report_date
+						FROM numbers(${days})
+					) dates
+					CROSS JOIN (
+						SELECT
+							person_id,
+							toDate(timestamp) as activity_date
 						FROM events
-						WHERE timestamp >= now() - INTERVAL ${weekStart} DAY
-							AND timestamp < now() - INTERVAL ${weekEnd} DAY
-							AND event = 'workspace_created'
-						GROUP BY person_id
-						HAVING active_days >= 3
-					)
-				`);
-
-				// Calculate the week's start date for the label
-				const weekDate = new Date();
-				weekDate.setDate(weekDate.getDate() - weekStart);
-				const weekLabel = weekDate.toISOString().split("T")[0] as string;
-
-				weeklyData.push({
-					week: weekLabel,
-					count: results[0]?.[0] ?? 0,
+						WHERE event = 'workspace_created'
+							AND timestamp >= now() - INTERVAL ${lookbackDays} DAY
+					) activities
+					WHERE activity_date > report_date - 7
+						AND activity_date <= report_date
+					GROUP BY report_date, person_id
+					HAVING active_days >= 3
+				)
+				GROUP BY report_date
+				ORDER BY report_date ASC
+			`);
+
+			// Create a map of existing data
+			const dataMap = new Map(results.map(([date, count]) => [date, count]));
+
+			// Fill in all dates in the range (in case some days have 0 WAU)
+			const filledData: { date: string; count: number }[] = [];
+			const now = new Date();
+			for (let i = days - 1; i >= 0; i--) {
+				const date = new Date(now);
+				date.setDate(date.getDate() - i);
+				const dateStr = date.toISOString().split("T")[0] as string;
+				filledData.push({
+					date: dateStr,
+					count: dataMap.get(dateStr) ?? 0,
 				});
 			}
 
-			return weeklyData;
+			return filledData;
 		}),
 
 	getRetention: adminProcedure.query(async () => {