diff --git a/graph-tutorial/package.json b/graph-tutorial/package.json
index 4c2c779..fc641ab 100644
--- a/graph-tutorial/package.json
+++ b/graph-tutorial/package.json
@@ -8,8 +8,8 @@
     "@microsoft/mgt-element": "^3.1.3",
     "@microsoft/microsoft-graph-client": "^3.0.7",
     "bootstrap": "^5.3.3",
-    "date-fns": "^2.29.2",
-    "date-fns-tz": "^2.0.1",
+    "date-fns": "4.1.0",
+    "date-fns-tz": "3.2.0",
     "react": "^18.3.1",
     "react-bootstrap": "^2.10.4",
     "react-dom": "^18.3.1",
diff --git a/graph-tutorial/src/GraphService.ts b/graph-tutorial/src/GraphService.ts
index ccf0a73..3fa2f7d 100644
--- a/graph-tutorial/src/GraphService.ts
+++ b/graph-tutorial/src/GraphService.ts
@@ -5,7 +5,7 @@
 import { Client, GraphRequestOptions, PageCollection, PageIterator } from '@microsoft/microsoft-graph-client';
 import { AuthCodeMSALBrowserAuthenticationProvider } from '@microsoft/microsoft-graph-client/authProviders/authCodeMsalBrowser';
 import { endOfWeek, startOfWeek } from 'date-fns';
-import { zonedTimeToUtc } from 'date-fns-tz';
+import { fromZonedTime } from 'date-fns-tz';
 import { User, Event } from '@microsoft/microsoft-graph-types';
 
 let graphClient: Client | undefined = undefined;
@@ -41,8 +41,8 @@ export async function getUserWeekCalendar(authProvider: AuthCodeMSALBrowserAuthe
   // Generate startDateTime and endDateTime query params
   // to display a 7-day window
   const now = new Date();
-  const startDateTime = zonedTimeToUtc(startOfWeek(now), timeZone).toISOString();
-  const endDateTime = zonedTimeToUtc(endOfWeek(now), timeZone).toISOString();
+  const startDateTime = fromZonedTime(startOfWeek(now), timeZone).toISOString();
+  const endDateTime = fromZonedTime(endOfWeek(now), timeZone).toISOString();
 
   // GET /me/calendarview?startDateTime=''&endDateTime=''
   // &$select=subject,organizer,start,end