diff --git a/.gitignore b/.gitignore
index ce5cb8e..7e0652c 100644
--- a/.gitignore
+++ b/.gitignore
@@ -24,9 +24,11 @@
 .DS_Store
 *.pem
 *.sqlite
-
-# debug
-npm-debug.log*
+# external experiments
+nova-calendar-main/
+
+# debug
+npm-debug.log*
 yarn-debug.log*
 yarn-error.log*
 .pnpm-debug.log*
diff --git a/src/app/layout.tsx b/src/app/layout.tsx
index 903a16c..336b058 100644
--- a/src/app/layout.tsx
+++ b/src/app/layout.tsx
@@ -1,3 +1,4 @@
+import "@/lib/performance-measure-polyfill"
 import type { Metadata } from "next"
 import "./globals.css"
 import { ConvexClientProvider } from "./ConvexClientProvider"
diff --git a/src/lib/performance-measure-polyfill.ts b/src/lib/performance-measure-polyfill.ts
new file mode 100644
index 0000000..311ff58
--- /dev/null
+++ b/src/lib/performance-measure-polyfill.ts
@@ -0,0 +1,41 @@
+export {}
+
+declare global {
+  var __performanceMeasurePatched: boolean | undefined
+}
+
+function isNegativeTimestampError(error: unknown): boolean {
+  if (!(error instanceof Error)) return false
+  return error.message.toLowerCase().includes("cannot have a negative time stamp")
+}
+
+if (typeof performance !== "undefined" && typeof performance.measure === "function") {
+  if (!globalThis.__performanceMeasurePatched) {
+    const originalMeasure = performance.measure.bind(performance)
+    performance.measure = ((name: string, startOrOptions?: string | PerformanceMeasureOptions, endMark?: string) => {
+      try {
+        return originalMeasure(name, startOrOptions as string | PerformanceMeasureOptions, endMark)
+      } catch (error) {
+        if (!isNegativeTimestampError(error)) {
+          throw error
+        }
+
+        // Next.js occasionally triggers an invalid interval when profiling slow routes.
+        // Clamp the measurement to start at 0 to avoid crashing the page.
+        if (typeof startOrOptions === "object" && startOrOptions) {
+          const safeOptions: PerformanceMeasureOptions = {
+            ...startOrOptions,
+            start: 0,
+          }
+          try {
+            return originalMeasure(name, safeOptions, endMark)
+          } catch {
+            return undefined
+          }
+        }
+        return undefined
+      }
+    }) as typeof performance.measure
+    globalThis.__performanceMeasurePatched = true
+  }
+}