diff --git a/src/app/telemetry/page.tsx b/src/app/telemetry/page.tsx
index 0d6cdf5..6d3dabe 100644
--- a/src/app/telemetry/page.tsx
+++ b/src/app/telemetry/page.tsx
@@ -92,8 +92,8 @@ export default function TelemetryPage() {
                 }
             }
             
-            const startUtc = startDate.toISOString()
-            const endUtc = endDate.toISOString()
+            const startUtc = startDate.toString();
+            const endUtc = endDate.toString();
 
             const result = await api.listTelemetry({ deviceId, startUtc, endUtc, pageSize: 100000 })
             setTelemetry(result.items)