From 65943e759919f3505cdb2500c775474630935e3a Mon Sep 17 00:00:00 2001
From: Chris <chrisvel@users.noreply.github.com>
Date: Fri, 13 Feb 2026 17:07:00 +0200
Subject: [PATCH] Fix remaining multi-weekday recurrence bugs (#838)

---
 backend/modules/tasks/operations/recurring.js | 19 ++++++++++++++++++-
 backend/modules/tasks/routes.js               |  5 +++++
 2 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/backend/modules/tasks/operations/recurring.js b/backend/modules/tasks/operations/recurring.js
index 00a478e..8ded1ff 100644
--- a/backend/modules/tasks/operations/recurring.js
+++ b/backend/modules/tasks/operations/recurring.js
@@ -148,7 +148,24 @@ async function calculateNextIterations(task, startFromDate, userTimezone) {
             );
         } else if (task.recurrence_type === 'weekly') {
             const interval = task.recurrence_interval || 1;
-            if (
+            if (task.recurrence_weekdays) {
+                const weekdays = Array.isArray(task.recurrence_weekdays)
+                    ? task.recurrence_weekdays
+                    : JSON.parse(task.recurrence_weekdays);
+                let found = false;
+                for (let daysAhead = 1; daysAhead <= 7; daysAhead++) {
+                    const testDate = new Date(nextDate);
+                    testDate.setUTCDate(testDate.getUTCDate() + daysAhead);
+                    if (weekdays.includes(testDate.getUTCDay())) {
+                        nextDate = testDate;
+                        found = true;
+                        break;
+                    }
+                }
+                if (!found) {
+                    nextDate.setUTCDate(nextDate.getUTCDate() + interval * 7);
+                }
+            } else if (
                 task.recurrence_weekday !== null &&
                 task.recurrence_weekday !== undefined
             ) {
diff --git a/backend/modules/tasks/routes.js b/backend/modules/tasks/routes.js
index 30d636d..fb9c13a 100644
--- a/backend/modules/tasks/routes.js
+++ b/backend/modules/tasks/routes.js
@@ -461,6 +461,7 @@ router.patch('/task/:uid', requireTaskWriteAccess, async (req, res) => {
             recurrence_interval,
             recurrence_end_date,
             recurrence_weekday,
+            recurrence_weekdays,
             recurrence_month_day,
             recurrence_week_of_month,
             completion_based,
@@ -504,6 +505,10 @@ router.patch('/task/:uid', requireTaskWriteAccess, async (req, res) => {
                         recurrence_weekday !== undefined
                             ? recurrence_weekday
                             : parentTask.recurrence_weekday,
+                    recurrence_weekdays:
+                        recurrence_weekdays !== undefined
+                            ? recurrence_weekdays
+                            : parentTask.recurrence_weekdays,
                     recurrence_month_day:
                         recurrence_month_day !== undefined
                             ? recurrence_month_day