diff --git a/src/features/organizations/components/organization-member-card.tsx b/src/features/organizations/components/organization-member-card.tsx
index edf8a721..f25e5d1c 100644
--- a/src/features/organizations/components/organization-member-card.tsx
+++ b/src/features/organizations/components/organization-member-card.tsx
@@ -57,7 +57,7 @@ export const OrganizationMemberCard = ({member, organization}: OrganizationMembe
                     <div className="font-medium">{member.user.name}</div>
                     <div className="text-sm text-muted-foreground">{member.user.email}</div>
                     <div
-                        className="text-xs text-muted-foreground">Joined {formatDayOnly(new Date(member.createdAt))}</div>
+                        className="text-xs text-muted-foreground">Joined {formatDayOnly(member.createdAt)}</div>
                 </div>
             </div>
             <div className="flex items-center space-x-2 mt-4 md:mt-0">
diff --git a/src/utils/date-formatting.ts b/src/utils/date-formatting.ts
index 88f95474..ad7964d7 100644
--- a/src/utils/date-formatting.ts
+++ b/src/utils/date-formatting.ts
@@ -38,13 +38,14 @@ export function formatDateLastContact(lastContact: string | number | Date | null
         : "Never connected.";
 }
 
-export function formatDayOnly(date: Date) {
+export function formatDayOnly(date: string | number | Date) {
+    const d = new Date(date);
     return new Intl.DateTimeFormat("en-GB", {
         day: "2-digit",
         month: "2-digit",
         year: "numeric",
         timeZone: TIMEZONE,
-    }).format(date);
+    }).format(d);
 }
 
 export function getTodayISODate() {