diff --git a/src/app/(protected)/workorders/_components/list/table/cells/appt-time-cell.tsx b/src/app/(protected)/workorders/_components/list/table/cells/appt-time-cell.tsx
index ff7fda7f..e43832d2 100644
--- a/src/app/(protected)/workorders/_components/list/table/cells/appt-time-cell.tsx
+++ b/src/app/(protected)/workorders/_components/list/table/cells/appt-time-cell.tsx
@@ -35,6 +35,20 @@ function slotStyle(active: boolean): React.CSSProperties {
   };
 }
 
+function nextStartSelection(
+  currentStart: string,
+  currentEnd: string,
+  slot: string,
+): { start: string; end: string } {
+  if (slot === currentStart) {
+    return { start: "", end: "" };
+  }
+  return {
+    start: slot,
+    end: currentEnd && currentEnd <= slot ? "" : currentEnd,
+  };
+}
+
 function ApptTimeSlotList({
   slots,
   active,
@@ -120,10 +134,9 @@ export function ApptTimeCell({ apptTime, onSave }: ApptTimeCellProps) {
               slots={TIME_SLOTS}
               active={start}
               onPick={(t) => {
-                setStart(t);
-                if (end && end <= t) {
-                  setEnd("");
-                }
+                const next = nextStartSelection(start, end, t);
+                setStart(next.start);
+                setEnd(next.end);
               }}
             />
           </div>
@@ -131,7 +144,13 @@ export function ApptTimeCell({ apptTime, onSave }: ApptTimeCellProps) {
             <Text as="p" className="px-3 pb-1 pt-2" style={SLOT_HEADER_SX}>
               End <span className="font-normal normal-case">(optional)</span>
             </Text>
-            <ApptTimeSlotList slots={endSlots} active={end} onPick={setEnd} />
+            <ApptTimeSlotList
+              slots={endSlots}
+              active={end}
+              onPick={(t) => {
+                setEnd(t === end ? "" : t);
+              }}
+            />
           </div>
         </div>
         <div className="flex items-center justify-between px-3 py-2">
diff --git a/src/test/app/(protected)/workorders/appt-time-cell.test.tsx b/src/test/app/(protected)/workorders/appt-time-cell.test.tsx
index 15aea687..07012d32 100644
--- a/src/test/app/(protected)/workorders/appt-time-cell.test.tsx
+++ b/src/test/app/(protected)/workorders/appt-time-cell.test.tsx
@@ -6,7 +6,7 @@ import {
   apptTimePopoverHint,
   commitApptTimeSelection,
 } from "@/domain/work-orders/utils/appt-time-selection";
-import { fmt12 } from "@/domain/work-orders/utils/wizard-date-utils";
+import { fmt12, formatApptRange } from "@/domain/work-orders/utils/wizard-date-utils";
 
 describe("apptTimePopoverHint", () => {
   it("asks for start when empty", () => {
@@ -100,6 +100,32 @@ describe("ApptTimeCell", () => {
     expect(onSave).not.toHaveBeenCalled();
   });
 
+  it("clears optional end when the selected end slot is toggled off", async () => {
+    const user = userEvent.setup();
+    const onSave = vi.fn();
+    render(<ApptTimeCell apptTime="09:00 – 11:00" onSave={onSave} />);
+
+    await user.click(screen.getByRole("button", { name: formatApptRange("09:00", "11:00") }));
+    const endSlots = await screen.findAllByRole("button", { name: fmt12("11:00") });
+    await user.click(endSlots[endSlots.length - 1]!);
+    await user.click(screen.getByRole("button", { name: /^done$/i }));
+
+    expect(onSave).toHaveBeenCalledWith("09:00");
+  });
+
+  it("clears start and end when the selected start slot is toggled off", async () => {
+    const user = userEvent.setup();
+    const onSave = vi.fn();
+    render(<ApptTimeCell apptTime="09:00 – 11:00" onSave={onSave} />);
+
+    await user.click(screen.getByRole("button", { name: formatApptRange("09:00", "11:00") }));
+    const startSlots = await screen.findAllByRole("button", { name: fmt12("09:00") });
+    await user.click(startSlots[0]!);
+    await user.click(screen.getByRole("button", { name: /^done$/i }));
+
+    expect(onSave).toHaveBeenCalledWith("");
+  });
+
   it("hydrates start-only stored times so Done can clear them", async () => {
     const user = userEvent.setup();
     const onSave = vi.fn();