diff --git a/scripts/src/hwlab-node-web-observe-runner-source.ts b/scripts/src/hwlab-node-web-observe-runner-source.ts
index a6dc028d..89ddc2c0 100644
--- a/scripts/src/hwlab-node-web-observe-runner-source.ts
+++ b/scripts/src/hwlab-node-web-observe-runner-source.ts
@@ -1706,18 +1706,25 @@ function buildPagePerformanceReport(samples, manifest) {
   const base = manifest?.baseUrl || "http://invalid.local";
   const seen = new Set();
   const groups = new Map();
+  const sampleTimes = samples.map((sample) => Date.parse(sample?.ts || "")).filter(Number.isFinite);
+  const windowStartMs = sampleTimes.length > 0 ? Math.min(...sampleTimes) : null;
+  const windowEndMs = sampleTimes.length > 0 ? Math.max(...sampleTimes) : null;
   for (const sample of samples) {
     const entries = Array.isArray(sample?.performance) ? sample.performance : [];
     for (const entry of entries) {
       const durationMs = Number(entry?.duration);
       if (!Number.isFinite(durationMs) || durationMs < 0) continue;
+      const entryCompletedMs = performanceEntryCompletedEpochMs(sample, entry);
+      if (windowStartMs !== null && entryCompletedMs !== null && entryCompletedMs < windowStartMs) continue;
+      if (windowEndMs !== null && entryCompletedMs !== null && entryCompletedMs > windowEndMs + 1000) continue;
+      const entryTs = entryCompletedMs === null ? (sample.ts ?? null) : new Date(entryCompletedMs).toISOString();
       const parsed = parsePerformanceUrl(entry?.name, base);
       if (!parsed.sameOrigin || !isApiLikePath(parsed.path)) continue;
       const normalizedPath = normalizeApiPath(parsed.path);
       const routeKind = classifyApiPerformanceRoute(normalizedPath, entry);
       const isLongLivedStream = routeKind === "same-origin-api-stream";
       const streamOpenMs = streamOpenLatencyMs(entry);
-      const dedupeKey = [parsed.path, entry.initiatorType || "", entry.startTime ?? "", Math.round(durationMs)].join("|");
+      const dedupeKey = [parsed.path, entry.initiatorType || "", sample?.pageProvenance?.pageLoadSeq ?? "", sample?.pageProvenance?.timeOrigin ?? "", entry.startTime ?? "", Math.round(durationMs)].join("|");
       if (seen.has(dedupeKey)) continue;
       seen.add(dedupeKey);
       const group = groups.get(normalizedPath) || {
@@ -1732,8 +1739,8 @@ function buildPagePerformanceReport(samples, manifest) {
         overFiveSecondCount: 0,
         streamLifetimeOverFiveSecondCount: 0,
         streamOpenOverFiveSecondCount: 0,
-        firstAt: sample.ts ?? null,
-        lastAt: sample.ts ?? null,
+        firstAt: entryTs,
+        lastAt: entryTs,
         firstSeq: sample.seq ?? null,
         lastSeq: sample.seq ?? null,
         initiatorTypes: [],
@@ -1758,8 +1765,8 @@ function buildPagePerformanceReport(samples, manifest) {
         group.overFiveSecondCount += 1;
         overBudget = true;
       }
-      if (overBudget && group.slowSamples.length < 80) group.slowSamples.push(compactPagePerformanceSlowSample({ sample, entry, normalizedPath, rawPath: parsed.path, durationMs, streamOpenMs }));
-      group.lastAt = sample.ts ?? null;
+      if (overBudget && group.slowSamples.length < 80) group.slowSamples.push(compactPagePerformanceSlowSample({ sample, entry, entryTs, normalizedPath, rawPath: parsed.path, durationMs, streamOpenMs }));
+      group.lastAt = entryTs;
       group.lastSeq = sample.seq ?? null;
       if (parsed.path && !group.rawPathSamples.includes(parsed.path)) group.rawPathSamples.push(parsed.path);
       if (entry.initiatorType && !group.initiatorTypes.includes(entry.initiatorType)) group.initiatorTypes.push(entry.initiatorType);
@@ -1826,9 +1833,20 @@ function buildPagePerformanceReport(samples, manifest) {
   };
 }
 
-function compactPagePerformanceSlowSample({ sample, entry, normalizedPath, rawPath, durationMs, streamOpenMs }) {
+function performanceEntryCompletedEpochMs(sample, entry) {
+  const origin = Number(sample?.pageProvenance?.timeOrigin);
+  const responseEnd = Number(entry?.responseEnd);
+  const startTime = Number(entry?.startTime);
+  const offset = Number.isFinite(responseEnd) && responseEnd > 0 ? responseEnd : startTime;
+  if (Number.isFinite(origin) && origin > 0 && Number.isFinite(offset) && offset >= 0) return Math.round(origin + offset);
+  const sampleTs = Date.parse(sample?.ts || "");
+  return Number.isFinite(sampleTs) ? sampleTs : null;
+}
+
+function compactPagePerformanceSlowSample({ sample, entry, entryTs, normalizedPath, rawPath, durationMs, streamOpenMs }) {
   return {
-    ts: sample?.ts ?? null,
+    ts: entryTs ?? sample?.ts ?? null,
+    sampleTs: sample?.ts ?? null,
     seq: sample?.seq ?? null,
     path: normalizedPath ?? null,
     rawPath: rawPath ?? null,