diff --git a/htdocs/js/DatePicker/datepicker.js b/htdocs/js/DatePicker/datepicker.js
index dca96fb2d8..eb469bb30f 100644
--- a/htdocs/js/DatePicker/datepicker.js
+++ b/htdocs/js/DatePicker/datepicker.js
@@ -55,7 +55,7 @@
 				groupRules[activeIndex][0]?.parentNode._flatpickr.selectedDates[0]?.getTime() ||
 				groupRules[activeIndex][1];
 
-			for (let i = 1; i < groupRules.length; ++i) {
+			for (let i = 0; i < groupRules.length; ++i) {
 				if (i == activeFieldDate) continue;
 				const thisFieldDate =
 					groupRules[i][0]?.parentNode._flatpickr.selectedDates[0]?.getTime() || groupRules[i][1];