From f202fe8bfed1194bdfecff15f2386c19c359097f Mon Sep 17 00:00:00 2001
From: "google-labs-jules[bot]"
 <161369871+google-labs-jules[bot]@users.noreply.github.com>
Date: Sat, 1 Aug 2026 04:25:12 +0000
Subject: [PATCH] perf(github): optimize calculateMostActiveDay by removing
 Date parsing in loop

Co-authored-by: is0692vs <135803462+is0692vs@users.noreply.github.com>
---
 src/lib/github.ts | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/src/lib/github.ts b/src/lib/github.ts
index d35c21bf..46d39698 100644
--- a/src/lib/github.ts
+++ b/src/lib/github.ts
@@ -89,14 +89,20 @@ function calculateStreaks(calendar: { count: number }[]): { longestStreak: numbe
 }
 
 function calculateMostActiveDay(calendar: { date: string; count: number }[]): string | null {
+  if (calendar.length === 0) {
+    return null;
+  }
+
   const weekdayNames = ["Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"];
   const weekdayTotals = Array.from({ length: 7 }, () => 0);
+  const startDay = new Date(`${calendar[0].date}T00:00:00Z`).getUTCDay();
 
-  for (const day of calendar) {
+  for (let i = 0; i < calendar.length; i++) {
+    const day = calendar[i];
     if (day.count === 0) {
       continue;
     }
-    const weekday = new Date(`${day.date}T00:00:00Z`).getUTCDay();
+    const weekday = (startDay + i) % 7;
     weekdayTotals[weekday] += day.count;
   }