diff --git a/lib/workers/repository/update/branch/schedule.spec.ts b/lib/workers/repository/update/branch/schedule.spec.ts
index ca3338350ef31e..2f9ab17bb2d089 100644
--- a/lib/workers/repository/update/branch/schedule.spec.ts
+++ b/lib/workers/repository/update/branch/schedule.spec.ts
@@ -239,6 +239,30 @@ describe('workers/repository/update/branch/schedule', () => {
       expect(res).toBeFalse();
     });
 
+    describe('supports cron syntax on Sundays', () => {
+      beforeEach(() => {
+        mockDate.set('2023-01-08T10:50:00.000'); // Locally Sunday 8 January 2023 10:50am
+      });
+
+      it('approves if the weekday is *', () => {
+        config.schedule = ['* * * * *'];
+        const res = schedule.isScheduledNow(config);
+        expect(res).toBeTrue();
+      });
+
+      it('approves if the weekday is 0', () => {
+        config.schedule = ['* * * * 0'];
+        const res = schedule.isScheduledNow(config);
+        expect(res).toBeTrue();
+      });
+
+      it('rejects if the weekday is 1', () => {
+        config.schedule = ['* * * * 1'];
+        const res = schedule.isScheduledNow(config);
+        expect(res).toBeFalse();
+      });
+    });
+
     describe('supports timezone', () => {
       const cases: [string, string, string, boolean][] = [
         ['after 4pm', 'Asia/Singapore', '2017-06-30T15:59:00.000+0800', false],
diff --git a/lib/workers/repository/update/branch/schedule.ts b/lib/workers/repository/update/branch/schedule.ts
index c4ace100418288..78bf22757189eb 100644
--- a/lib/workers/repository/update/branch/schedule.ts
+++ b/lib/workers/repository/update/branch/schedule.ts
@@ -98,7 +98,7 @@ function cronMatches(cron: string, now: DateTime): boolean {
     return false;
   }
 
-  if (parsedCron.weekDays.indexOf(now.weekday) === -1) {
+  if (!parsedCron.weekDays.includes(now.weekday % 7)) {
     // Weekdays mismatch
     return false;
   }