diff --git a/src/utils/date/range.ts b/src/utils/date/range.ts
index 7fccc8c4..7e287589 100644
--- a/src/utils/date/range.ts
+++ b/src/utils/date/range.ts
@@ -181,8 +181,8 @@ export class DateRangeContext {
 
   render(data: RangeData, range: DateRange, days: DayParts[]) {
     let result = null;
-    const startDayIndex = days[0].dayIndex;
-    const endDayIndex = days[days.length - 1].dayIndex;
+    const startDayIndex = days[0]?.dayIndex ?? 0;
+    const endDayIndex = days[days.length - 1]?.dayIndex ?? 0;
     if (range.hasRepeat) {
       days.forEach(day => {
         if (range.startsOnDay(day)) {