diff --git a/frontend/src/app/(dashboard)/appointments/page.tsx b/frontend/src/app/(dashboard)/appointments/page.tsx
index bbea8c0..b40d35e 100644
--- a/frontend/src/app/(dashboard)/appointments/page.tsx
+++ b/frontend/src/app/(dashboard)/appointments/page.tsx
@@ -285,7 +285,6 @@ export default function AppointmentsPage() {
           <div className="flex flex-col sm:flex-row sm:items-end gap-4 sm:justify-between">
             <ScheduleDayPicker
               value={scheduleDate}
-              minDate={todayStart}
               onChange={(d) => setScheduleDate(startOfLocalDay(d))}
             />
             {loadingSchedule && (
diff --git a/frontend/src/components/ui/shared/ScheduleDayPicker.tsx b/frontend/src/components/ui/shared/ScheduleDayPicker.tsx
index 99518f5..1684f56 100644
--- a/frontend/src/components/ui/shared/ScheduleDayPicker.tsx
+++ b/frontend/src/components/ui/shared/ScheduleDayPicker.tsx
@@ -2,17 +2,11 @@
 
 import { useEffect, useId, useRef, useState } from 'react';
 import { ChevronDown, ChevronLeft, ChevronRight } from 'lucide-react';
-import {
-  addCalendarDays,
-  compareLocalDayStart,
-  startOfLocalDay,
-} from '@/lib/appointmentTime';
+import { addCalendarDays, startOfLocalDay } from '@/lib/appointmentTime';
 
 interface ScheduleDayPickerProps {
   value: Date;
   onChange: (day: Date) => void;
-  /** Optional lower bound for day selection and previous-day navigation. */
-  minDate?: Date;
   label?: string;
 }
 
@@ -39,27 +33,10 @@ function buildLocalDay(year: number, month: number, day: number): Date {
   return new Date(year, month, day, 0, 0, 0, 0);
 }
 
-function clampToValidDay(
-  year: number,
-  month: number,
-  day: number,
-  min?: Date,
-): Date {
-  const maxDay = daysInMonth(year, month);
-  let next = buildLocalDay(year, month, Math.min(Math.max(1, day), maxDay));
-  if (min) {
-    const floor = startOfLocalDay(min);
-    if (compareLocalDayStart(next, floor) < 0) {
-      next = floor;
-    }
-  }
-  return next;
-}
-
-function yearRange(min?: Date, anchor?: Date): number[] {
-  const now = new Date();
-  const startYear = min ? min.getFullYear() : now.getFullYear() - 5;
-  const endYear = Math.max(now.getFullYear() + 2, anchor?.getFullYear() ?? now.getFullYear());
+function yearRange(anchor: Date): number[] {
+  const anchorYear = anchor.getFullYear();
+  const startYear = anchorYear - 10;
+  const endYear = anchorYear + 2;
   const years: number[] = [];
   for (let y = startYear; y <= endYear; y += 1) {
     years.push(y);
@@ -72,21 +49,18 @@ const selectClassName = `
   bg-background-card/90 text-text-primary text-sm
   pl-2 pr-7 py-1.5
   focus:outline-none focus:ring-2 focus:ring-primary/35 focus:border-border-strong
-  disabled:opacity-50 disabled:cursor-not-allowed
 `;
 
-export function ScheduleDayPicker({
-  value,
-  onChange,
-  minDate,
-  label = 'Schedule date',
-}: ScheduleDayPickerProps) {
+/**
+ * Calendar day navigator (arrows + year/month/day panel).
+ * Does not restrict past dates — parent pages enforce read-only vs editable for schedule grids/forms.
+ */
+export function ScheduleDayPicker({ value, onChange, label = 'Schedule date' }: ScheduleDayPickerProps) {
   const panelId = useId();
   const rootRef = useRef<HTMLDivElement>(null);
   const [panelOpen, setPanelOpen] = useState(false);
 
   const normalizedValue = startOfLocalDay(value);
-  const normalizedMin = minDate ? startOfLocalDay(minDate) : undefined;
 
   const labelText = normalizedValue.toLocaleDateString(undefined, {
     weekday: 'short',
@@ -95,28 +69,20 @@ export function ScheduleDayPicker({
     year: 'numeric',
   });
 
-  const previousDay = addCalendarDays(normalizedValue, -1);
-  const canGoPrevious =
-    !normalizedMin || compareLocalDayStart(previousDay, normalizedMin) >= 0;
-
-  const years = yearRange(normalizedMin, normalizedValue);
+  const years = yearRange(normalizedValue);
   const selectedYear = normalizedValue.getFullYear();
   const selectedMonth = normalizedValue.getMonth();
   const selectedDay = normalizedValue.getDate();
   const dayCount = daysInMonth(selectedYear, selectedMonth);
 
   function applyParts(year: number, month: number, day: number, closePanel = false) {
-    onChange(clampToValidDay(year, month, day, normalizedMin));
+    const maxDay = daysInMonth(year, month);
+    onChange(buildLocalDay(year, month, Math.min(Math.max(1, day), maxDay)));
     if (closePanel) {
       setPanelOpen(false);
     }
   }
 
-  function handlePreviousDay() {
-    if (!canGoPrevious) return;
-    onChange(previousDay);
-  }
-
   useEffect(() => {
     if (!panelOpen) return;
 
@@ -146,9 +112,8 @@ export function ScheduleDayPicker({
       <div className="flex items-center gap-1 rounded-[var(--radius-md)] border border-border bg-background-secondary/90 px-1 py-1 shadow-[inset_0_1px_0_rgba(255,255,255,0.02)]">
         <button
           type="button"
-          onClick={handlePreviousDay}
-          disabled={!canGoPrevious}
-          className="shrink-0 rounded-[var(--radius-sm)] p-2 text-text-muted hover:text-text-primary hover:bg-background-card/80 focus:outline-none focus:ring-2 focus:ring-primary/35 disabled:opacity-40 disabled:pointer-events-none"
+          onClick={() => onChange(addCalendarDays(normalizedValue, -1))}
+          className="shrink-0 rounded-[var(--radius-sm)] p-2 text-text-muted hover:text-text-primary hover:bg-background-card/80 focus:outline-none focus:ring-2 focus:ring-primary/35"
           aria-label="Previous day"
         >
           <ChevronLeft className="h-4 w-4 icon-flat" />
@@ -232,17 +197,11 @@ export function ScheduleDayPicker({
                   }
                   className={selectClassName}
                 >
-                  {MONTH_LABELS.map((name, index) => {
-                    const disabled =
-                      normalizedMin &&
-                      selectedYear === normalizedMin.getFullYear() &&
-                      index < normalizedMin.getMonth();
-                    return (
-                      <option key={name} value={index} disabled={disabled}>
-                        {name}
-                      </option>
-                    );
-                  })}
+                  {MONTH_LABELS.map((name, index) => (
+                    <option key={name} value={index}>
+                      {name}
+                    </option>
+                  ))}
                 </select>
                 <ChevronDown
                   className="pointer-events-none absolute right-1.5 top-1/2 h-3.5 w-3.5 -translate-y-1/2 text-text-muted icon-flat"
@@ -272,18 +231,11 @@ export function ScheduleDayPicker({
                   }
                   className={selectClassName}
                 >
-                  {Array.from({ length: dayCount }, (_, i) => i + 1).map((day) => {
-                    const disabled =
-                      normalizedMin &&
-                      selectedYear === normalizedMin.getFullYear() &&
-                      selectedMonth === normalizedMin.getMonth() &&
-                      day < normalizedMin.getDate();
-                    return (
-                      <option key={day} value={day} disabled={disabled}>
-                        {day}
-                      </option>
-                    );
-                  })}
+                  {Array.from({ length: dayCount }, (_, i) => i + 1).map((day) => (
+                    <option key={day} value={day}>
+                      {day}
+                    </option>
+                  ))}
                 </select>
                 <ChevronDown
                   className="pointer-events-none absolute right-1.5 top-1/2 h-3.5 w-3.5 -translate-y-1/2 text-text-muted icon-flat"
diff --git a/frontend/src/components/ui/treatment/AppointmentsStrip.tsx b/frontend/src/components/ui/treatment/AppointmentsStrip.tsx
index ddb4405..15cc3a4 100644
--- a/frontend/src/components/ui/treatment/AppointmentsStrip.tsx
+++ b/frontend/src/components/ui/treatment/AppointmentsStrip.tsx
@@ -12,8 +12,6 @@ interface AppointmentsStripProps {
   onToggleStripHidden: () => void;
   selectedDay: Date;
   onSelectDay: (day: Date) => void;
-  /** Same lower bound as Appointments schedule (cannot pick days before this). */
-  minScheduleDate: Date;
   appointments: TreatmentAppointment[];
   selectedAppointmentId: string | null;
   onSelectAppointment: (id: string) => void;
@@ -25,7 +23,6 @@ export function AppointmentsStrip({
   onToggleStripHidden,
   selectedDay,
   onSelectDay,
-  minScheduleDate,
   appointments,
   selectedAppointmentId,
   onSelectAppointment,
@@ -65,7 +62,6 @@ export function AppointmentsStrip({
       <div className="flex flex-col sm:flex-row sm:items-end gap-4 sm:justify-between">
         <ScheduleDayPicker
           value={selectedDay}
-          minDate={minScheduleDate}
           onChange={(d) => onSelectDay(startOfLocalDay(d))}
         />
         {loading && (
diff --git a/frontend/src/components/ui/treatment/TreatmentWorkspace.tsx b/frontend/src/components/ui/treatment/TreatmentWorkspace.tsx
index bd2bc9f..1e7230f 100644
--- a/frontend/src/components/ui/treatment/TreatmentWorkspace.tsx
+++ b/frontend/src/components/ui/treatment/TreatmentWorkspace.tsx
@@ -9,7 +9,7 @@ import { Button } from '@/components/ui/shared/Button';
 import { Dropdown } from '@/components/ui/shared/Dropdown';
 import { SearchBar } from '@/components/ui/shared/SearchBar';
 import { Toast } from '@/components/ui/shared/Toast';
-import { isSameLocalCalendarDay, startOfLocalDay } from '@/lib/appointmentTime';
+import { compareLocalDayStart, isSameLocalCalendarDay, startOfLocalDay } from '@/lib/appointmentTime';
 import {
   fetchLinkedOrganizations,
   fetchMyAppointmentsForDay,
@@ -54,7 +54,7 @@ export function TreatmentWorkspace({ userId, currentOrganization }: TreatmentWor
 
   const [stripHidden, setStripHidden] = useState(false);
 
-  const scheduleMinDate = useMemo(() => startOfLocalDay(new Date()), []);
+  const todayStart = useMemo(() => startOfLocalDay(new Date()), []);
 
   const [selectedDay, setSelectedDay] = useState(() => startOfLocalDay(new Date()));
   const [appointments, setAppointments] = useState<TreatmentAppointment[]>([]);
@@ -87,6 +87,13 @@ export function TreatmentWorkspace({ userId, currentOrganization }: TreatmentWor
     [appointments, selectedAppointmentId],
   );
 
+  const isViewingPastDay = useMemo(
+    () => compareLocalDayStart(selectedDay, todayStart) < 0,
+    [selectedDay, todayStart],
+  );
+
+  const canEditTreatmentForDay = Boolean(selectedAppointment) && !isViewingPastDay;
+
   const activeRecord = useMemo(
     () => records.find((r) => r.clientId === activeRecordId) ?? records[0],
     [records, activeRecordId],
@@ -339,13 +346,19 @@ export function TreatmentWorkspace({ userId, currentOrganization }: TreatmentWor
         onToggleStripHidden={() => setStripHidden((s) => !s)}
         selectedDay={selectedDay}
         onSelectDay={setSelectedDay}
-        minScheduleDate={scheduleMinDate}
         appointments={appointments}
         selectedAppointmentId={selectedAppointmentId}
         onSelectAppointment={onPickAppointment}
         loading={apptsLoading}
       />
 
+      {isViewingPastDay && (
+        <p className="text-sm text-text-secondary rounded-[var(--radius-md)] border border-border/60 bg-background-secondary/50 px-3 py-2">
+          Past days are view-only. You can review appointments and history, but treatment records
+          cannot be added or changed.
+        </p>
+      )}
+
       <div className="grid grid-cols-1 xl:grid-cols-[minmax(280px,380px)_minmax(0,1fr)] gap-6 items-start">
         <div className="space-y-4">
           {selectedAppointment ? (
@@ -423,7 +436,7 @@ export function TreatmentWorkspace({ userId, currentOrganization }: TreatmentWor
           <FdiToothChart
             selected={selectedTeethSet}
             onToggle={toggleTooth}
-            disabled={!selectedAppointment}
+            disabled={!canEditTreatmentForDay}
           />
 
           <div className="surface-card p-4 space-y-4">
@@ -437,7 +450,7 @@ export function TreatmentWorkspace({ userId, currentOrganization }: TreatmentWor
               <Button
                 type="button"
                 variant="primary"
-                disabled={!selectedAppointment}
+                disabled={!canEditTreatmentForDay}
                 onClick={() => {
                   const nr = newRecord();
                   fixActiveAfterRecordsChange([...records, nr]);
@@ -486,7 +499,7 @@ export function TreatmentWorkspace({ userId, currentOrganization }: TreatmentWor
                     }}
                     placeholder="Write clinical notes for this record…"
                     rows={5}
-                    disabled={!selectedAppointment}
+                    disabled={!canEditTreatmentForDay}
                     className="mt-1.5 w-full rounded-[var(--radius-md)] border border-border bg-background-secondary/90 text-text-primary text-sm px-3 py-2 placeholder:text-text-muted focus:outline-none focus:ring-2 focus:ring-primary/35 resize-y min-h-[120px]"
                   />
                 </label>
@@ -503,7 +516,7 @@ export function TreatmentWorkspace({ userId, currentOrganization }: TreatmentWor
                         ),
                       );
                     }}
-                    disabled={!selectedAppointment}
+                    disabled={!canEditTreatmentForDay}
                     className="capitalize"
                     style={{ color: treatmentTypeTextColor }}
                   >
@@ -522,7 +535,7 @@ export function TreatmentWorkspace({ userId, currentOrganization }: TreatmentWor
                     id="treatment-record-attachments"
                     type="file"
                     multiple
-                    disabled={!selectedAppointment}
+                    disabled={!canEditTreatmentForDay}
                     onChange={(e) => {
                       addAttachments(e.target.files);
                       e.target.value = '';
@@ -533,7 +546,7 @@ export function TreatmentWorkspace({ userId, currentOrganization }: TreatmentWor
                   <Button
                     type="button"
                     variant="primary"
-                    disabled={!selectedAppointment}
+                    disabled={!canEditTreatmentForDay}
                     onClick={() => attachmentInputRef.current?.click()}
                     aria-controls="treatment-record-attachments"
                   >
@@ -589,7 +602,7 @@ export function TreatmentWorkspace({ userId, currentOrganization }: TreatmentWor
                       <Checkbox
                         key={o.id}
                         checked={activeRecord.sendToOrganizationIds.includes(o.id)}
-                        disabled={!selectedAppointment || Boolean(activeRecord.sentAt)}
+                        disabled={!canEditTreatmentForDay || Boolean(activeRecord.sentAt)}
                         onChange={(checked) => {
                           setRecords((prev) =>
                             prev.map((r) => {
@@ -614,7 +627,7 @@ export function TreatmentWorkspace({ userId, currentOrganization }: TreatmentWor
                   <Button
                     type="button"
                     variant="primary"
-                    disabled={!selectedAppointment || Boolean(activeRecord.sentAt) || sendBusyId === activeRecord.clientId}
+                    disabled={!canEditTreatmentForDay || Boolean(activeRecord.sentAt) || sendBusyId === activeRecord.clientId}
                     isLoading={sendBusyId === activeRecord.clientId}
                     onClick={() => void handleSendRecord(activeRecord)}
                   >
@@ -633,7 +646,7 @@ export function TreatmentWorkspace({ userId, currentOrganization }: TreatmentWor
               <Button
                 type="button"
                 variant="primary"
-                disabled={!selectedAppointment || saveBusy}
+                disabled={!canEditTreatmentForDay || saveBusy}
                 isLoading={saveBusy}
                 onClick={() => void handleSaveAll()}
               >