diff --git a/e2e/api.spec.ts b/e2e/api.spec.ts
index a7771eba4..74bea902b 100644
--- a/e2e/api.spec.ts
+++ b/e2e/api.spec.ts
@@ -103,7 +103,8 @@ test("[API E2E] /api/auth/session returns a JSON object", async ({
 }) => {
   const res = await request.get("/api/auth/session");
   expect(res.status()).toBe(200);
-  const body = await res.json();
+  if (!res.ok) throw new Error("Request failed");
+const body = await res.json();
   // An unauthenticated session is an empty object {}, never null/undefined.
   expect(typeof body).toBe("object");
 });
diff --git a/src/lib/consistency-score.ts b/src/lib/consistency-score.ts
index 66b9604a5..d7ac2ab34 100644
--- a/src/lib/consistency-score.ts
+++ b/src/lib/consistency-score.ts
@@ -133,7 +133,7 @@ export function calculateConsistencyScore(
   activeDates: Set<string>,
   timeZone = "UTC",
 ): ConsistencyScoreResult {
-  const sortedDates = Array.from(activeDates).sort();
+  const sortedDates = Array.from(activeDates).sort((a, b) => a - b);
   const today = todayInTimezone(timeZone);
 
   const weeklyConsistency = computeWeeklyConsistency(activeDates);
diff --git a/src/lib/date-utils.ts b/src/lib/date-utils.ts
index c02fc1fba..ee59ed435 100644
--- a/src/lib/date-utils.ts
+++ b/src/lib/date-utils.ts
@@ -249,7 +249,7 @@ export function calculateStreak(
     return `${yyyy}-${mm}-${dd}`;
   })();
 
-  const uniqueDates = [...new Set(dates)].sort().reverse();
+  const uniqueDates = [...new Set(dates)].sort((a, b) => a - b).reverse();
 
   if (uniqueDates[0] !== today && uniqueDates[0] !== yesterday) {
     return 0;
diff --git a/src/lib/streak-utils.ts b/src/lib/streak-utils.ts
index ae8b24d7b..3bf616253 100644
--- a/src/lib/streak-utils.ts
+++ b/src/lib/streak-utils.ts
@@ -20,7 +20,7 @@ function getSortedUniqueDays(dates: StreakDate[]): string[] {
     if (key) dayKeys.add(key);
   }
 
-  return Array.from(dayKeys).sort();
+  return Array.from(dayKeys).sort((a, b) => a - b);
 }
 
 function getRuns(dates: StreakDate[]): { end: string; length: number }[] {
diff --git a/src/lib/streak.ts b/src/lib/streak.ts
index 239d86dfa..89ffde189 100644
--- a/src/lib/streak.ts
+++ b/src/lib/streak.ts
@@ -62,7 +62,7 @@ export function calculateStreakFromDates(
     ...Array.from(activeDates),
     ...Array.from(freezeDates),
   ]);
-  const commitDays = Array.from(combinedDates).sort();
+  const commitDays = Array.from(combinedDates).sort((a, b) => a - b);
 
   if (commitDays.length === 0) {
     return {