diff --git a/public/assets/i18n/en/period.json b/public/assets/i18n/en/period.json
index 7d68ab8..08baa94 100644
--- a/public/assets/i18n/en/period.json
+++ b/public/assets/i18n/en/period.json
@@ -1,7 +1,8 @@
 {
-  "invoices": "Invoices have been or have to be invoices for a period from <strong>{{from}}</strong> to <strong>{{to}}</strong>.",
-  "text": "If a part of this period is over and related invoices have been billed, you can close the timeframe.",
-  "text-more": "This function can be useful for example when you want to close an accounting year.",
+  "invoices": "Invoices have been or need to be issued for the period from <strong>{{from}}</strong> to <strong>{{to}}</strong>.",
+  "no_invoices": "Invoices are issued or need to be issued for an unspecified period.",
+  "text": "If a portion of this period has elapsed and the related invoices have been issued, you may close the timeframe.",
+  "text-more": "This function can be useful, for instance, when you need to close an accounting year.",
   "close": "Close selected period",
   "alert": {
     "warning": "WARNING",
diff --git a/src/pages/period/Period.tsx b/src/pages/period/Period.tsx
index 5220b2a..fe76558 100644
--- a/src/pages/period/Period.tsx
+++ b/src/pages/period/Period.tsx
@@ -93,6 +93,24 @@ const Period: React.FC = () => {
     await initPeriod();
   };
 
+  const renderPeriod = () => {
+    if (period?.from === undefined && period?.to === undefined) {
+      return <p className={`${styles.text} ion-padding-top`}>{t('period:no_invoices')}</p>;
+    }
+
+    return (
+      <p
+        className={`${styles.text} ion-padding-top`}
+        dangerouslySetInnerHTML={{
+          __html: t('period:invoices', {
+            from: format(period?.from) ?? t('period:unknown'),
+            to: format(period?.to) ?? t('period:unknown'),
+          }),
+        }}
+      ></p>
+    );
+  };
+
   return (
     <IonPage>
       <IonContent>
@@ -106,15 +124,7 @@ const Period: React.FC = () => {
           </IonHeader>
 
           <LocalizationProvider dateAdapter={AdapterDateFns}>
-            <p
-              className={`${styles.text} ion-padding-top`}
-              dangerouslySetInnerHTML={{
-                __html: t('period:invoices', {
-                  from: format(period?.from) ?? t('period:unknown'),
-                  to: format(period?.to) ?? t('period:unknown'),
-                }),
-              }}
-            ></p>
+            {renderPeriod()}
 
             <p>{t('period:text')}</p>