Hide unsettled GitHub traffic days from the catalog pulse

web/src/components/CatalogCharts.svelte

@@ -2,6 +2,7 @@
   import { formatCount } from "../lib/format.js";
   import {
     catalogTrafficTotals,
+    cutUnsettledDays,
     dailyCatalogPulse,
     pulseBars,
     quietStarsRank,
@@ -17,7 +18,7 @@
   $: totals = catalogTrafficTotals(repos);
   $: visitors = rankTraffic(repos, "view_uniques", 10);
   $: cloners = rankTraffic(repos, "clone_uniques", 10);
-  $: pulse = pulseBars(dailyCatalogPulse(repos));
+  $: pulse = pulseBars(cutUnsettledDays(dailyCatalogPulse(repos)));
   $: languages = uniqueVisitorsByLanguage(repos);
   $: quiet = quietStarsRank(repos).map((row) => ({
     ...row,
@@ -62,7 +63,7 @@
       <section class="chart-panel chart-panel-wide" aria-labelledby="chart-pulse">
         <header class="chart-head">
           <h3 id="chart-pulse">Last 14 days</h3>
-          <p>Unique visitors and cloners summed across this catalog.</p>
+          <p>Unique visitors and cloners summed across this catalog. GitHub settles traffic with a ~1–2 day delay, so the newest days appear once they are final.</p>
         </header>
         <div class="pulse-chart">
           {#each pulse as day}

web/src/lib/trafficCharts.js

@@ -75,6 +75,15 @@ export function dailyCatalogPulse(repos) {
   return fillDaySpan(rows);
 }
 
+// GitHub finalizes a traffic day roughly 36h after it closes, so the newest
+// buckets come back empty or partial. Hide them so the pulse ends on settled data.
+const SETTLE_HOURS = 36;
+
+export function cutUnsettledDays(days, now = new Date(), settleHours = SETTLE_HOURS) {
+  const cutoff = now.getTime() - settleHours * 3600 * 1000;
+  return (days || []).filter((day) => Date.parse(`${day.date}T00:00:00Z`) <= cutoff);
+}
+
 function pulseHeight(value, peak) {
   if (value <= 0) return "0%";
   return `${Math.max(6, Math.round((value / peak) * 100))}%`;

web/src/lib/trafficCharts.test.js

@@ -1,6 +1,7 @@
 import { describe, expect, test } from "vitest";
 import {
   catalogTrafficTotals,
+  cutUnsettledDays,
   dailyCatalogPulse,
   pulseBars,
   quietStarsRank,
@@ -119,6 +120,34 @@ describe("dailyCatalogPulse", () => {
   });
 });
 
+describe("cutUnsettledDays", () => {
+  const pulse = [
+    { date: "2026-09-16", viewUniques: 5, cloneUniques: 2 },
+    { date: "2026-09-17", viewUniques: 3, cloneUniques: 1 },
+    { date: "2026-09-18", viewUniques: 0, cloneUniques: 0 },
+    { date: "2026-09-19", viewUniques: 0, cloneUniques: 0 },
+  ];
+
+  test("drops trailing days GitHub has not settled yet", () => {
+    const now = new Date("2026-09-19T03:00:00Z");
+    expect(cutUnsettledDays(pulse, now).map((day) => day.date)).toEqual(["2026-09-16", "2026-09-17"]);
+  });
+
+  test("keeps a day once it is older than the settle window", () => {
+    const now = new Date("2026-09-19T13:00:00Z");
+    expect(cutUnsettledDays(pulse, now).map((day) => day.date)).toEqual([
+      "2026-09-16",
+      "2026-09-17",
+      "2026-09-18",
+    ]);
+  });
+
+  test("returns an empty list when every day is unsettled", () => {
+    const fresh = [{ date: "2026-09-19", viewUniques: 1, cloneUniques: 0 }];
+    expect(cutUnsettledDays(fresh, new Date("2026-09-19T03:00:00Z"))).toEqual([]);
+  });
+});
+
 describe("pulseBars", () => {
   test("labels UTC days and scales both series to the same peak", () => {
     const bars = pulseBars(dailyCatalogPulse(catalog));