diff --git a/frontend/src/components/Layout.jsx b/frontend/src/components/Layout.jsx
index df84538..ddcf49e 100644
--- a/frontend/src/components/Layout.jsx
+++ b/frontend/src/components/Layout.jsx
@@ -259,7 +259,7 @@ const Layout = ({ children }) => {
 		const dateObj = new Date(date);
 
 		// Check if date is valid
-		if (isNaN(dateObj.getTime())) return "Invalid date";
+		if (Number.isNaN(dateObj.getTime())) return "Invalid date";
 
 		const diff = now - dateObj;
 		const seconds = Math.floor(diff / 1000);
diff --git a/frontend/src/pages/Settings.jsx b/frontend/src/pages/Settings.jsx
index 355bdb3..fdcc7c1 100644
--- a/frontend/src/pages/Settings.jsx
+++ b/frontend/src/pages/Settings.jsx
@@ -580,7 +580,7 @@ const Settings = () => {
 										value={formData.updateInterval}
 										onChange={(e) => {
 											const val = parseInt(e.target.value);
-											if (!isNaN(val)) {
+											if (!Number.isNaN(val)) {
 												handleInputChange(
 													"updateInterval",
 													Math.min(1440, Math.max(5, val)),