[scheduler] Build the last counted day of a daily series only when it counts one

With an interval of millennia, the day before the first one fell before the
supported years, which the constructor of the plain dates rejects.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Author: flaviendelangle

packages/x-scheduler-internals-premium/src/internals/utils/recurring-events/RecurringSeries.test.ts

@@ -205,6 +205,17 @@ describe('recurring-events/RecurringSeries', () => {
       ).to.equal(100);
     });
 
+    it('should return count when target is before start with an interval of millennia', () => {
+      expect(
+        countRemaining(
+          createRule(1_000_000),
+          adapter.date('2025-03-10', 'UTC'),
+          adapter.date('2025-03-09T23:59:59', 'UTC'),
+          100,
+        ),
+      ).to.equal(100);
+    });
+
     it('should return the remaining occurrences after an inclusive day span (interval=1)', () => {
       expect(
         countRemaining(

packages/x-scheduler-internals-premium/src/internals/utils/recurring-events/RecurringSeries.ts

@@ -480,7 +480,9 @@ export class RecurringSeries {
       const startDayNumber = getDayNumber(startDay);
       const days = getDayNumber(date) - startDayNumber;
       count = days > 0 ? Math.min(this.count, Math.ceil(days / ruleDays.interval)) : 0;
-      lastDay = plainDateFromDayNumber(startDayNumber + (count - 1) * ruleDays.interval);
+      if (count > 0) {
+        lastDay = plainDateFromDayNumber(startDayNumber + (count - 1) * ruleDays.interval);
+      }
     } else {
       count = countDays(() => false);
     }