diff --git a/src/PowderCoating.Web/Controllers/AppointmentsController.cs b/src/PowderCoating.Web/Controllers/AppointmentsController.cs
index 9418f0a..bfefd92 100644
--- a/src/PowderCoating.Web/Controllers/AppointmentsController.cs
+++ b/src/PowderCoating.Web/Controllers/AppointmentsController.cs
@@ -381,9 +381,15 @@ public class AppointmentsController : Controller
                 return View(dto);
             }
 
-            // Map changes
+            // Map changes — capture old start before overwrite so we can detect a reschedule.
+            var previousStart = appointment.ScheduledStartTime;
             _mapper.Map(dto, appointment);
 
+            // If the appointment was rescheduled, clear the reminder stamp so the background
+            // service will fire again at the new time.
+            if (appointment.ScheduledStartTime != previousStart)
+                appointment.ReminderSentAt = null;
+
             // Update
             await _unitOfWork.Appointments.UpdateAsync(appointment);
             await _unitOfWork.CompleteAsync();
@@ -725,6 +731,8 @@ public class AppointmentsController : Controller
             var duration = appointment.ScheduledEndTime - appointment.ScheduledStartTime;
             appointment.ScheduledStartTime = start;
             appointment.ScheduledEndTime = end;
+            // Drag-drop always changes the time — reset so the reminder fires at the new time.
+            appointment.ReminderSentAt = null;
 
             await _unitOfWork.Appointments.UpdateAsync(appointment);
             await _unitOfWork.CompleteAsync();