diff --git a/src/lang/english.txt b/src/lang/english.txt
index cd17ce0cc5..f105d5861f 100644
--- a/src/lang/english.txt
+++ b/src/lang/english.txt
@@ -5087,6 +5087,7 @@ STR_ERROR_AIRCRAFT_NOT_ENOUGH_RANGE                             :{WHITE}... airc
 STR_ERROR_CAN_T_TIMETABLE_VEHICLE                               :{WHITE}Can't timetable vehicle...
 STR_ERROR_TIMETABLE_ONLY_WAIT_AT_STATIONS                       :{WHITE}Vehicles can only wait at stations
 STR_ERROR_TIMETABLE_NOT_STOPPING_HERE                           :{WHITE}This vehicle is not stopping at this station
+STR_ERROR_TIMETABLE_INCOMPLETE                                  :{WHITE}... timetable is incomplete
 
 # Sign related errors
 STR_ERROR_TOO_MANY_SIGNS                                        :{WHITE}... too many signs
diff --git a/src/timetable_cmd.cpp b/src/timetable_cmd.cpp
index f800b25ae6..e43dee3022 100644
--- a/src/timetable_cmd.cpp
+++ b/src/timetable_cmd.cpp
@@ -288,7 +288,7 @@ CommandCost CmdSetTimetableStart(DoCommandFlag flags, VehicleID veh_id, bool tim
 	if (start_date < 0 || start_date > MAX_DAY) return CMD_ERROR;
 	if (start_date - _date > 15 * DAYS_IN_LEAP_YEAR) return CMD_ERROR;
 	if (_date - start_date > DAYS_IN_LEAP_YEAR) return CMD_ERROR;
-	if (timetable_all && !v->orders->IsCompleteTimetable()) return CMD_ERROR;
+	if (timetable_all && !v->orders->IsCompleteTimetable()) return CommandCost(STR_ERROR_TIMETABLE_INCOMPLETE);
 	if (timetable_all && start_date + total_duration / DAY_TICKS > MAX_DAY) return CMD_ERROR;
 
 	if (flags & DC_EXEC) {
diff --git a/src/timetable_gui.cpp b/src/timetable_gui.cpp
index f6b1e3da93..27d2254e1f 100644
--- a/src/timetable_gui.cpp
+++ b/src/timetable_gui.cpp
@@ -530,7 +530,7 @@ struct TimetableWindow : Window {
 			}
 
 			case WID_VT_START_DATE: // Change the date that the timetable starts.
-				ShowSetDateWindow(this, v->index, _date, _cur_year, _cur_year + 15, ChangeTimetableStartCallback, reinterpret_cast<void *>(static_cast<uintptr_t>(v->orders->IsCompleteTimetable() && _ctrl_pressed)));
+				ShowSetDateWindow(this, v->index, _date, _cur_year, _cur_year + 15, ChangeTimetableStartCallback, reinterpret_cast<void *>(static_cast<uintptr_t>(_ctrl_pressed)));
 				break;
 
 			case WID_VT_CHANGE_TIME: { // "Wait For" button.