Show booked days in plan date picker

src/app/plan/plan.css

@@ -162,15 +162,20 @@
 .plan-calendar-title { display: inline-flex; align-items: center; gap: 7px; font-size: 12px; font-weight: 800; }
 .plan-calendar-actions { display: flex; gap: 2px; }
 .plan-calendar-actions button { display: grid; width: 28px; height: 28px; place-items: center; border-radius: 6px; color: var(--text-secondary); }
-.plan-calendar-hint { margin: 3px 0 13px; color: var(--text-muted); font-size: 10px; }
+.plan-calendar-hint { margin: 3px 0 5px; color: var(--text-muted); font-size: 10px; }
+.plan-calendar-booking-key { display: flex; align-items: center; gap: 6px; margin: 0 0 12px; color: var(--text-muted); font-size: 10px; }
+.plan-calendar-booking-key span { width: 10px; height: 10px; flex: none; border: 1px solid var(--plan-amber); border-radius: 3px; background: color-mix(in srgb, var(--plan-amber) 24%, var(--surface)); }
 .plan-calendar-grid { display: grid; grid-template-columns: repeat(7, minmax(0, 1fr)); gap: 2px; }
 .plan-weekday { display: grid; height: 26px; place-items: center; color: var(--text-muted); font-size: 9px; font-weight: 800; }
-.plan-calendar-day { display: grid; height: 34px; place-items: center; border-radius: 7px; color: var(--text-secondary); font-size: 11px; font-variant-numeric: tabular-nums; }
+.plan-calendar-day { position: relative; display: grid; height: 34px; place-items: center; border-radius: 7px; color: var(--text-secondary); font-size: 11px; font-variant-numeric: tabular-nums; }
 .plan-calendar-day:hover { background: var(--surface-raised); }
 .plan-calendar-day.is-outside { opacity: .38; }
 .plan-calendar-day.is-today { outline: 1px solid var(--brand); outline-offset: -2px; }
 .plan-calendar-day.is-between { border-radius: 0; background: var(--brand-soft); }
 .plan-calendar-day.is-selected { background: var(--brand); color: var(--brand-fg); font-weight: 800; }
+.plan-calendar-day.is-booked:not(.is-selected):not(.is-between) { background: color-mix(in srgb, var(--plan-amber) 24%, var(--surface)); box-shadow: inset 0 0 0 1px color-mix(in srgb, var(--plan-amber) 75%, transparent); }
+.plan-calendar-day.is-booked:not(.is-selected):not(.is-between):hover { background: color-mix(in srgb, var(--plan-amber) 37%, var(--surface)); }
+.plan-calendar-day.is-booked::after { position: absolute; right: 4px; bottom: 3px; width: 4px; height: 4px; border-radius: 50%; background: var(--plan-amber); content: ""; }
 .plan-dialog-bottom { align-items: flex-end; gap: 14px; padding: 20px 25px 24px; }
 .plan-item-dialog { width: min(100%, 560px); max-height: calc(100vh - 40px); overflow-y: auto; border: 1px solid var(--border-subtle); border-radius: 17px; background: var(--panel); box-shadow: 0 22px 70px #0017285c; }
 .plan-item-top { display: flex; align-items: flex-start; justify-content: space-between; gap: 16px; padding: 24px 27px 18px; border-bottom: 1px solid var(--border-subtle); }

src/components/planning/date-range-dialog.test.ts

@@ -0,0 +1,29 @@
+import { createElement } from "react";
+import { renderToStaticMarkup } from "react-dom/server";
+import { describe, expect, it } from "vitest";
+
+import { DateRangeDialog } from "@/components/planning/date-range-dialog";
+
+describe("planning date picker", () => {
+  it("marks another item's dates while leaving those days selectable", () => {
+    const html = renderToStaticMarkup(createElement(DateRangeDialog, {
+      cardTitle: "Current work",
+      projectName: "Client project",
+      initial: { start: "2026-10-05", end: "2026-10-06" },
+      boardTargetDate: "",
+      bookings: [{
+        draftRange: { start: "2026-09-30", end: "2026-10-02" },
+        approvedRange: null,
+      }],
+      pending: false,
+      onSave: () => undefined,
+      onClose: () => undefined,
+    }));
+
+    expect(html).toContain("Other work planned · dates can overlap");
+    const bookedDay = html.match(/<button[^>]*aria-label="2026-10-01, 1 other work item planned"[^>]*>1<\/button>/)?.[0];
+    expect(bookedDay).toContain("is-booked");
+    expect(bookedDay).not.toContain("disabled");
+    expect(html).toContain('aria-label="2026-10-03"');
+  });
+});

src/components/planning/date-range-dialog.tsx

@@ -3,7 +3,7 @@
 import { useEffect, useRef, useState } from "react";
 import { CalendarDays, ChevronLeft, ChevronRight, X } from "lucide-react";
 
-import { addDays, todayLocalIso } from "@/lib/planning/calendar";
+import { addDays, bookedItemCount, todayLocalIso, type CalendarBooking } from "@/lib/planning/calendar";
 import { validPlanRange, type PlanRange } from "@/lib/planning/state";
 
 interface DateRangeDialogProps {
@@ -11,6 +11,7 @@ interface DateRangeDialogProps {
   projectName: string;
   initial: PlanRange | null;
   boardTargetDate: string;
+  bookings: CalendarBooking[];
   pending: boolean;
   onSave: (range: PlanRange | null) => void;
   onClose: () => void;
@@ -40,6 +41,7 @@ export function DateRangeDialog({
   projectName,
   initial,
   boardTargetDate,
+  bookings,
   pending,
   onSave,
   onClose,
@@ -148,19 +150,22 @@ export function DateRangeDialog({
             </div>
           </div>
           <p className="plan-calendar-hint">{choosingEnd ? "Choose the end date" : "Choose a start date, then an end date"}</p>
+          <p className="plan-calendar-booking-key"><span aria-hidden="true" /> Other work planned · dates can overlap</p>
           <div className="plan-calendar-grid">
             {WEEKDAYS.map((day) => <span key={day} className="plan-weekday">{day}</span>)}
             {monthDays(month).map(({ date, inMonth }) => {
               const selected = date === start || date === end;
               const between = date > start && date < end;
+              const booked = bookedItemCount(date, bookings);
               return (
                 <button
                   key={date}
                   type="button"
                   onClick={() => pickDate(date)}
-                  className={`plan-calendar-day${inMonth ? "" : " is-outside"}${selected ? " is-selected" : ""}${between ? " is-between" : ""}${date === today ? " is-today" : ""}`}
-                  aria-label={date}
+                  className={`plan-calendar-day${inMonth ? "" : " is-outside"}${selected ? " is-selected" : ""}${between ? " is-between" : ""}${date === today ? " is-today" : ""}${booked ? " is-booked" : ""}`}
+                  aria-label={`${date}${booked ? `, ${booked} other ${booked === 1 ? "work item" : "work items"} planned` : ""}`}
                   aria-pressed={selected}
+                  title={booked ? `${booked} other ${booked === 1 ? "work item" : "work items"} planned · overlaps allowed` : undefined}
                 >
                   {Number(date.slice(-2))}
                 </button>

src/components/planning/plan-board.tsx

@@ -29,6 +29,7 @@ import {
   shiftCalendar,
   todayLocalIso,
   type CalendarAxis,
+  type CalendarBooking,
   type CalendarZoom,
 } from "@/lib/planning/calendar";
 import type { PlanningCard, PlanningProject } from "@/lib/planning/load";
@@ -91,6 +92,11 @@ export function PlanBoard({ projects, role }: { projects: PlanningProject[]; rol
   const waiting = board.filter((project) => project.plan.status === "submitted").length;
   const editProject = board.find((project) => project.id === editing?.projectId);
   const editCard = editProject?.cards.find((card) => card.id === editing?.cardId);
+  const otherBookings: CalendarBooking[] = editing
+    ? board.flatMap((project) => project.cards
+      .filter((card) => project.id !== editing.projectId || card.id !== editing.cardId)
+      .map((card) => ({ draftRange: card.draftRange, approvedRange: card.approvedRange })))
+    : [];
   const detailsProject = board.find((project) => project.id === details?.projectId);
   const detailsCard = detailsProject?.cards.find((card) => card.id === details?.cardId);
 
@@ -327,6 +333,7 @@ export function PlanBoard({ projects, role }: { projects: PlanningProject[]; rol
           projectName={`${editProject.clientName} · ${editProject.name}`}
           initial={editCard.draftRange}
           boardTargetDate={editCard.boardTargetDate}
+          bookings={otherBookings}
           pending={pending}
           onSave={saveRange}
           onClose={() => !pending && setEditing(null)}

src/lib/planning/calendar.test.ts

@@ -1,6 +1,6 @@
 import { describe, expect, it } from "vitest";
 
-import { calendarAxis, rangePixels } from "@/lib/planning/calendar";
+import { bookedItemCount, calendarAxis, rangePixels } from "@/lib/planning/calendar";
 
 describe("planning calendar", () => {
   it("places a short task on exact daily columns", () => {
@@ -20,4 +20,16 @@ describe("planning calendar", () => {
       width: 2 * axis.dayWidth,
     });
   });
+
+  it("marks inclusive booked days across months and counts each work item once", () => {
+    const bookings = [
+      { draftRange: { start: "2026-09-30", end: "2026-10-02" }, approvedRange: { start: "2026-09-30", end: "2026-10-01" } },
+      { draftRange: null, approvedRange: { start: "2026-10-01", end: "2026-10-03" } },
+    ];
+    expect(bookedItemCount("2026-09-29", bookings)).toBe(0);
+    expect(bookedItemCount("2026-09-30", bookings)).toBe(1);
+    expect(bookedItemCount("2026-10-01", bookings)).toBe(2);
+    expect(bookedItemCount("2026-10-03", bookings)).toBe(1);
+    expect(bookedItemCount("2026-10-04", bookings)).toBe(0);
+  });
 });

src/lib/planning/calendar.ts

@@ -11,6 +11,20 @@ export interface CalendarAxis {
   groups: { label: string; startDay: number; days: number }[];
 }
 
+export interface CalendarBooking {
+  draftRange: PlanRange | null;
+  approvedRange: PlanRange | null;
+}
+
+/** Count work items once per day, even when their draft and approved dates overlap. */
+export function bookedItemCount(date: string, bookings: CalendarBooking[]): number {
+  return bookings.reduce((count, booking) => {
+    const coversDate = (range: PlanRange | null) =>
+      range !== null && range.start <= date && date <= range.end;
+    return count + (coversDate(booking.draftRange) || coversDate(booking.approvedRange) ? 1 : 0);
+  }, 0);
+}
+
 const DAY_MS = 86_400_000;
 
 export function todayLocalIso(): string {