diff --git a/components/calendar/__tests__/calendar-day-view-phone.test.tsx b/components/calendar/__tests__/calendar-day-view-phone.test.tsx
new file mode 100644
index 000000000..c7365c4c4
--- /dev/null
+++ b/components/calendar/__tests__/calendar-day-view-phone.test.tsx
@@ -0,0 +1,66 @@
+import { render, screen, within } from '@testing-library/react';
+import { describe, it, expect, vi } from 'vitest';
+import { CalendarDayView } from '../calendar-day-view';
+import type { Calendar, CalendarEvent, CalendarTask } from '@/lib/jmap/types';
+
+// CAL-27 follow-up: the phone day view drew tasks as 10px chips with a
+// circle too small to tap, and a busy neighbouring day left an empty
+// all-day block of ~150px above the hours of a day with none.
+
+const calendars = [{ id: 'cal-1', name: 'Work', color: '#123456' }] as unknown as Calendar[];
+
+const holiday = {
+  id: 'ev-1', calendarIds: { 'cal-1': true }, title: 'Holiday', start: '2026-09-10T00:00:00',
+  duration: 'P1D', showWithoutTime: true,
+} as unknown as CalendarEvent;
+
+const task = {
+  id: 't1', '@type': 'Task', title: 'Buy milk', calendarIds: { 'cal-1': true },
+  progress: 'needs-action', priority: 0, due: '2026-09-09', showWithoutTime: true,
+} as unknown as CalendarTask;
+
+function renderDay(isMobile: boolean, tasks: CalendarTask[] = [task]) {
+  return render(
+    <CalendarDayView
+      focus={{ date: new Date(2026, 8, 9), nonce: 0 }}
+      windowKey="day:2026-09-08"
+      rangeStart={new Date(2026, 8, 8)}
+      rangeEnd={new Date(2026, 8, 10)}
+      selectedDate={new Date(2026, 8, 9)}
+      events={[holiday]}
+      calendars={calendars}
+      tasks={tasks}
+      onSelectEvent={vi.fn()}
+      onCreateAtTime={vi.fn()}
+      isMobile={isMobile}
+    />,
+  );
+}
+
+describe('day view on a phone', () => {
+  it('gives each task a full row with a 44px target for the circle', () => {
+    renderDay(true);
+    const chip = document.querySelector<HTMLElement>('[data-calendar-task="t1"]')!;
+    expect(chip).toHaveClass('min-h-11', 'text-xs');
+    expect(within(chip).getByRole('button', { name: /mark_complete|Mark as complete/i })).toHaveClass('w-11', 'self-stretch');
+  });
+
+  it('keeps the small shared chip on a wide screen', () => {
+    renderDay(false);
+    const chip = document.querySelector<HTMLElement>('[data-calendar-task="t1"]')!;
+    expect(chip).toHaveClass('h-full', 'text-[10px]');
+  });
+
+  it('sizes the all-day row by the day in view, not by a busy neighbour', () => {
+    renderDay(true, []);
+    const today = document.querySelector<HTMLElement>('[data-day="2026-09-09"]')!;
+    const next = document.querySelector<HTMLElement>('[data-day="2026-09-10"]')!;
+    // The day in view has nothing all-day: no empty block under its date.
+    expect(within(today).queryByText(/all_day|All day/i)).toBeNull();
+    expect(today).not.toHaveClass('h-0');
+    // The neighbour's all-day event takes no height of its own.
+    expect(within(next).getByRole('button', { name: /Holiday/ })).toBeInTheDocument();
+    expect(next).toHaveClass('h-0', 'min-h-full', 'overflow-hidden');
+    expect(screen.getAllByRole('columnheader')).toHaveLength(3);
+  });
+});
diff --git a/components/calendar/calendar-day-view.tsx b/components/calendar/calendar-day-view.tsx
index d927ee602..b2518068b 100644
--- a/components/calendar/calendar-day-view.tsx
+++ b/components/calendar/calendar-day-view.tsx
@@ -197,14 +197,6 @@ export function CalendarDayView({
     return map;
   }, [days, eventsByDay, hours]);
 
-  const hasAllDayArea = useMemo(
-    () => days.some((day) => {
-      const key = format(day, "yyyy-MM-dd");
-      return (eventsByDay.get(key)?.allDay.length ?? 0) > 0 || (tasksByDay.get(key)?.length ?? 0) > 0;
-    }),
-    [days, eventsByDay, tasksByDay],
-  );
-
   const scrollToFocus = useCallback(() => {
     const root = rootRef.current;
     if (!root) return;
@@ -232,6 +224,10 @@ export function CalendarDayView({
   // not used: browsers re-snap on their own when columns are prepended,
   // which would double the scroll correction.)
   const visibleKeyRef = useRef<string | null>(null);
+  // The day in view: its all-day events and tasks size the row under the
+  // dates, so a busy neighbour doesn't leave an empty block above the hours.
+  const [visibleKey, setVisibleKey] = useState(() => dayKey(focus.date));
+  useEffect(() => { setVisibleKey(dayKey(focus.date)); }, [focus.date, focus.nonce]);
   const scrollFrameRef = useRef<number | null>(null);
   const snapTimerRef = useRef<ReturnType<typeof setTimeout> | null>(null);
   const handleStripScroll = useCallback(() => {
@@ -255,6 +251,7 @@ export function CalendarDayView({
       const key = dayKey(day);
       if (key === visibleKeyRef.current) return;
       visibleKeyRef.current = key;
+      setVisibleKey(key);
       onVisibleDateChange?.(day);
     });
   }, [colWidth, colCount, days, onVisibleDateChange]);
@@ -352,7 +349,16 @@ export function CalendarDayView({
               const allDayEvents = eventsByDay.get(key)?.allDay ?? [];
               const dayTasks = tasksByDay.get(key) ?? [];
               return (
-                <div key={key} data-day={key} className="min-w-0 border-e border-border last:border-e-0">
+                <div
+                  key={key}
+                  data-day={key}
+                  className={cn(
+                    "min-w-0 border-e border-border last:border-e-0",
+                    // Other days take no height of their own: they fill the
+                    // row the day in view sets, clipped while swiping past.
+                    key !== visibleKey && "h-0 min-h-full overflow-hidden",
+                  )}
+                >
                   <div
                     className={cn("flex flex-col items-start gap-0.5 px-3 pt-2 pb-1.5", isMobile && "px-2")}
                     role="columnheader"
@@ -376,7 +382,7 @@ export function CalendarDayView({
                     <PluginDayLabel surface="calendar-day-header" date={key} className="w-full" />
                   </div>
 
-                  {hasAllDayArea && (
+                  {(allDayEvents.length > 0 || dayTasks.length > 0) && (
                     <div
                       className="px-4 py-2 border-t border-border"
                       onContextMenu={onContextMenuEmpty ? (e) => {
@@ -414,12 +420,13 @@ export function CalendarDayView({
                           <div className="space-y-0.5">
                             {/* The same chip as the month and week grids. */}
                             {dayTasks.map((task) => (
-                              <div key={task.id} className="h-5">
+                              <div key={task.id} className={isMobile ? undefined : "h-5"}>
                                 <CalendarTaskChip
                                   task={task}
                                   calendar={calendars.find((c) => task.calendarIds[c.id])}
                                   onToggleComplete={onToggleTaskComplete}
                                   onSelect={onSelectTask}
+                                  touch={isMobile}
                                 />
                               </div>
                             ))}
diff --git a/components/calendar/task-chip.tsx b/components/calendar/task-chip.tsx
index ccea5a78d..7df48a12d 100644
--- a/components/calendar/task-chip.tsx
+++ b/components/calendar/task-chip.tsx
@@ -10,6 +10,8 @@ interface CalendarTaskChipProps {
   calendar?: Calendar;
   onToggleComplete?: (task: CalendarTask) => void;
   onSelect?: (task: CalendarTask) => void;
+  /** A full row for a finger: 44px tall, a bigger circle with a 44px hit area (phone day view). */
+  touch?: boolean;
   className?: string;
 }
 
@@ -17,7 +19,7 @@ interface CalendarTaskChipProps {
  * A task on its due day in the month and week grids (#1107). The circle
  * toggles completion; the title opens the task in the editor.
  */
-export function CalendarTaskChip({ task, calendar, onToggleComplete, onSelect, className }: CalendarTaskChipProps) {
+export function CalendarTaskChip({ task, calendar, onToggleComplete, onSelect, touch = false, className }: CalendarTaskChipProps) {
   const t = useTranslations("calendar");
   const isCompleted = task.progress === "completed";
   const color = calendar?.color || "#3b82f6";
@@ -26,30 +28,39 @@ export function CalendarTaskChip({ task, calendar, onToggleComplete, onSelect, c
   return (
     <div
       data-calendar-task={task.id}
-      className={cn("h-full rounded text-[10px] font-medium flex items-center overflow-hidden", className)}
+      className={cn(
+        "rounded font-medium flex items-center overflow-hidden",
+        touch ? "min-h-11 text-xs" : "h-full text-[10px]",
+        className,
+      )}
       style={{ backgroundColor: `${color}20`, borderInlineStart: `3px solid ${color}` }}
     >
       <button
         type="button"
         onClick={(e) => { e.stopPropagation(); onToggleComplete?.(task); }}
-        className="group h-full ps-1 pe-0.5 flex items-center flex-shrink-0"
+        className={cn(
+          "group flex items-center flex-shrink-0",
+          touch ? "self-stretch w-11 justify-center" : "h-full ps-1 pe-0.5",
+        )}
         aria-label={isCompleted ? t("tasks.mark_incomplete") : t("tasks.mark_complete")}
       >
         <span
           className={cn(
-            "w-2.5 h-2.5 rounded-full border flex items-center justify-center",
+            "rounded-full border flex items-center justify-center",
+            touch ? "w-4 h-4" : "w-2.5 h-2.5",
             isCompleted ? "bg-success border-success text-success-foreground" : "group-hover:bg-background",
           )}
           style={isCompleted ? undefined : { borderColor: color }}
         >
-          {isCompleted && <Check className="h-2 w-2" />}
+          {isCompleted && <Check className={touch ? "h-3 w-3" : "h-2 w-2"} />}
         </span>
       </button>
       <button
         type="button"
         onClick={(e) => { e.stopPropagation(); onSelect?.(task); }}
         className={cn(
-          "h-full flex-1 min-w-0 truncate text-start pe-1 hover:opacity-80",
+          "flex-1 min-w-0 truncate text-start pe-1 hover:opacity-80",
+          touch ? "self-stretch" : "h-full",
           isCompleted && "line-through text-muted-foreground",
         )}
         title={title}