fix: key drag targets by date, not weekday, in views wider than a week

The drop preview and the empty-slot input were keyed by date.getDay(), which
is only unique inside a 7-day window. At 21 days every column sharing the
hovered column's weekday lit up — the mirrored drop targets, one per Tuesday.

The invisible half was worse: handleDrop resolved its target with
visibleDays.find(d => d.getDay() === dayOfWeek), so dropping on the second or
third Tuesday scheduled the task on the first one. Both now use the column's
own date; handleDragOver/handleDrop take a Date instead of a weekday number.

Task rendering was already date-based, so only drag state was affected.

v1.115.3

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

CHANGELOG.md

@@ -2,6 +2,21 @@
 
 All notable changes to this project are documented in this file.
 
+## [1.115.3] - 2026-09-03
+
+### Fixed
+- Drag & drop in views wider than 7 days: the drop target was keyed by weekday
+  (`date.getDay()`), which is only unique inside a 7-day window. In a 21-day view every
+  column sharing the weekday of the hovered one lit up as a drop target — three mirrored
+  highlights, one per Tuesday. Now keyed by the local date.
+- Same bug, worse half: `handleDrop` resolved the target date with
+  `visibleDays.find(d => d.getDay() === dayOfWeek)`, so dropping a task on the second or
+  third Tuesday of a wide view silently scheduled it on the *first* Tuesday. The drop now
+  uses the column's own date. Tasks dragged in a >7-day view before this fix may sit on the
+  wrong date.
+- The inline "click an empty slot to add a task" input had the same weekday key, so clicking
+  one slot opened an input in every column with that weekday.
+
 ## [1.115.2] - 2026-09-03
 
 ### Changed

package-lock.json

@@ -1,12 +1,12 @@
 {
   "name": "my-weekly-todo-list",
-  "version": "1.115.2",
+  "version": "1.115.3",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "my-weekly-todo-list",
-      "version": "1.115.2",
+      "version": "1.115.3",
       "license": "MIT",
       "dependencies": {
         "@auth/prisma-adapter": "^2.11.1",

package.json

@@ -1,6 +1,6 @@
 {
   "name": "my-weekly-todo-list",
-  "version": "1.115.2",
+  "version": "1.115.3",
   "description": "A web-based weekly task management application that organizes to-dos and calendar events in a single, intuitive weekly view",
   "main": "index.js",
   "scripts": {

src/components/WeeklyView.tsx

@@ -1071,8 +1071,10 @@ export default function WeeklyView() {
     const [slideDirection, setSlideDirection] = useState<"next" | "prev" | null>(
         null,
     );
+    // Keyed by local date ("YYYY-MM-DD"), not by weekday: with more than 7 visible day
+    // columns a weekday matches several columns at once, which lit up every Tuesday.
     const [activeSlot, setActiveSlot] = useState<{
-        day: number;
+        dateKey: string;
         slot: string;
     } | null>(null);
     const [newSlotTask, setNewSlotTask] = useState("");
@@ -1081,7 +1083,7 @@ export default function WeeklyView() {
     );
     const [currentTime, setCurrentTime] = useState(new Date());
     const [dropPreview, setDropPreview] = useState<{
-        day?: number;
+        dateKey?: string;
         slot?: string;
         listId?: string;
         slotIdx?: number;
@@ -5023,7 +5025,7 @@ export default function WeeklyView() {
 
     const handleDragOver = (
         e: DragEvent | React.DragEvent,
-        dayOfWeek?: number,
+        date?: Date,
         slot?: string,
     ) => {
         // Reject someday list drags on day slots
@@ -5039,17 +5041,16 @@ export default function WeeklyView() {
             e.dataTransfer.dropEffect = "move";
         }
         // Update drop preview if we have day and slot info
-        if (dayOfWeek !== undefined && slot) {
-            setDropPreview({ day: dayOfWeek, slot });
+        if (date && slot) {
+            setDropPreview({ dateKey: formatDateToISO(date), slot });
         }
     };
 
-    const handleDrop = async (e: DragEvent, dayOfWeek: number, slot?: string) => {
+    const handleDrop = async (e: DragEvent, date: Date, slot?: string) => {
         e.preventDefault();
         if (draggedTask) {
-            const visibleDays = getVisibleDays();
-            const targetDateObj =
-                visibleDays.find((d) => d.getDay() === dayOfWeek) || new Date();
+            const targetDateObj = date;
+            const dayOfWeek = targetDateObj.getDay();
 
             let targetSlot = slot;
 
@@ -7652,7 +7653,7 @@ export default function WeeklyView() {
                                             const isHourStart = minutes === "00";
                                             const slotEvents = getEventsForSlot(date, slot);
                                             const isActive =
-                                                activeSlot?.day === date.getDay() &&
+                                                activeSlot?.dateKey === formatDateToISO(date) &&
                                                 activeSlot?.slot === slot;
                                             const isProtected = isSlotProtected(date, slot);
                                             const isOccupiedByTask = isSlotOccupiedByTask(date, slot, draggedTask?.id);
@@ -7674,7 +7675,7 @@ export default function WeeklyView() {
                                                 }
 
                                                 if (!isActive) {
-                                                    setActiveSlot({ day: date.getDay(), slot });
+                                                    setActiveSlot({ dateKey: formatDateToISO(date), slot });
                                                     setNewSlotTask("");
                                                 }
                                             };
@@ -7694,11 +7695,11 @@ export default function WeeklyView() {
                                             const handleSlotDrop = (e: React.DragEvent) => {
                                                 e.preventDefault();
                                                 if (isProtected || isOccupiedByTask) return; // Don't allow dropping on protected or occupied slots
-                                                handleDrop(e, date.getDay(), slot);
+                                                handleDrop(e, date, slot);
                                             };
 
                                             const isDropTarget =
-                                                dropPreview?.day === date.getDay() &&
+                                                dropPreview?.dateKey === formatDateToISO(date) &&
                                                 dropPreview?.slot === slot;
 
                                             const dateStr = `${date.getFullYear()}-${String(date.getMonth() + 1).padStart(2, '0')}-${String(date.getDate()).padStart(2, '0')}`;
@@ -7736,7 +7737,7 @@ export default function WeeklyView() {
                                                     }}
                                                     onDragOver={(e) =>
                                                         !isProtected && !isOccupiedByTask &&
-                                                        handleDragOver(e, date.getDay(), slot)
+                                                        handleDragOver(e, date, slot)
                                                     }
                                                     onDrop={handleSlotDrop}
                                                 >
@@ -7947,8 +7948,8 @@ export default function WeeklyView() {
                                     </div>
                                 ) : (
                                     <div
-                                        onDragOver={(e) => handleDragOver(e, date.getDay())}
-                                        onDrop={(e) => handleDrop(e, date.getDay())}
+                                        onDragOver={(e) => handleDragOver(e, date)}
+                                        onDrop={(e) => handleDrop(e, date)}
                                         onDragLeave={handleDragLeave}
                                         style={{ flex: 1 }}
                                     >