diff --git a/src/components/WellTreeSelector.tsx b/src/components/WellTreeSelector.tsx
index cb22068..3d4a421 100644
--- a/src/components/WellTreeSelector.tsx
+++ b/src/components/WellTreeSelector.tsx
@@ -9,9 +9,10 @@ import { WellIcon, WellIconState } from './icons/WellIcon'
 import { ReactComponent as DepositIcon } from '../images/DepositIcon.svg'
 import { ReactComponent as ClusterIcon } from '../images/ClusterIcon.svg'
 import { DepositDto } from '../services/api'
+import { RawDate } from '../utils/DateTimeUtils'
 
 export const getWellState = (idState?: number): WellIconState => idState === 1 ? 'active' : 'unknown'
-export const checkIsWellOnline = (lastTelemetryDate?: string | number | Date | null): boolean => {
+export const checkIsWellOnline = (lastTelemetryDate?: RawDate): boolean => {
     if (!lastTelemetryDate) return false
     return Date.now() - +new Date(lastTelemetryDate) < 600_000
 }
diff --git a/src/utils/DateTimeUtils.ts b/src/utils/DateTimeUtils.ts
new file mode 100644
index 0000000..79a8063
--- /dev/null
+++ b/src/utils/DateTimeUtils.ts
@@ -0,0 +1,5 @@
+export type RawDate = number | string | Date
+
+export function isRawDate(value: unknown): value is RawDate {
+    return isNaN(new Date(value as RawDate).getTime())
+}