fix

public/js/modals/email-modal.js

@@ -43,16 +43,20 @@ function parseLocalDate(dateValue) {
     return Number.isNaN(d.getTime()) ? null : d;
 }
 
-function getLastSentDate(invoice) {
+function getFirstSentDate(invoice) {
     const sentDates = Array.isArray(invoice.sent_dates)
         ? invoice.sent_dates.filter(Boolean)
         : [];
 
-    if (sentDates.length > 0) {
-        return sentDates[sentDates.length - 1];
+    if (sentDates.length === 0) {
+        return null;
     }
 
-    return null;
+    const sortedDates = sentDates
+        .map(d => String(d).split('T')[0])
+        .sort();
+
+    return sortedDates[0];
 }
 
 function getTermDays(invoice) {
@@ -79,18 +83,13 @@ function addDays(dateValue, days) {
 }
 
 function getEffectiveDueDate(invoice) {
-    const lastSentDate = getLastSentDate(invoice);
+    const firstSentDate = getFirstSentDate(invoice);
 
-    // Nie versendet = kein Reminder/Overdue Text
-    if (!lastSentDate) {
+    if (!firstSentDate) {
         return null;
     }
 
-    if (invoice.due_date) {
-        return parseLocalDate(invoice.due_date);
-    }
-
-    return addDays(lastSentDate, getTermDays(invoice));
+    return addDays(firstSentDate, getTermDays(invoice));
 }
 
 function getOverdueDays(invoice) {