diff --git a/changelog.md b/changelog.md
index 2116f320..cadbc6c4 100644
--- a/changelog.md
+++ b/changelog.md
@@ -29,6 +29,7 @@ Saves from 2.3 are not compatible with 2.4.
 * **[UI]** Aircraft for a new flight are now only selectable if they match the task type for that flight.
 * **[UI]** WIP - There is now a unit info button for each unit in the recruitment list, that should help newer players learn what each unit does.
 * **[UI]** Docs for time-on-target and creating new theaters/factions/loadouts are now linked in the UI at the appropriate places.
+* **[UI]** ASAP is now a checkbox rather than a button. Enabling this will disable the TOT selector but changes to the package structure will automatically re-ASAP the package.
 * **[Factions]** Added option for date-based loadout restriction. Active radar homing missiles are handled, patches welcome for the other thousand weapons.
 * **[Factions]** Added Poland 2010 faction.
 * **[Factions]** Added Greece 2005 faction.
diff --git a/gen/ato.py b/gen/ato.py
index fd7da75f..99a76789 100644
--- a/gen/ato.py
+++ b/gen/ato.py
@@ -20,6 +20,7 @@ from game.theater.missiontarget import MissionTarget
 from game.utils import Speed
 from .flights.flight import Flight, FlightType
 from .flights.flightplan import FormationFlightPlan
+from .flights.traveltime import TotEstimator
 
 
 @dataclass(frozen=True)
@@ -54,6 +55,11 @@ class Package:
 
     delay: int = field(default=0)
 
+    #: True if the package ToT should be reset to ASAP whenever the player makes
+    #: a change. This is really a UI property rather than a game property, but
+    #: we want it to persist in the save.
+    auto_asap: bool = field(default=False)
+
     #: Desired TOT as an offset from mission start.
     time_over_target: timedelta = field(default=timedelta())
 
@@ -127,6 +133,9 @@ class Package:
             return max(times)
         return None
 
+    def set_tot_asap(self) -> None:
+        self.time_over_target = TotEstimator(self).earliest_tot()
+
     def add_flight(self, flight: Flight) -> None:
         """Adds a flight to the package."""
         self.flights.append(flight)
diff --git a/qt_ui/dialogs.py b/qt_ui/dialogs.py
index 263bfb62..09fd2b93 100644
--- a/qt_ui/dialogs.py
+++ b/qt_ui/dialogs.py
@@ -60,7 +60,7 @@ class Dialog:
         """Opens the dialog to edit the given flight."""
         cls.edit_flight_dialog = QEditFlightDialog(
             cls.game_model,
-            package_model.package,
+            package_model,
             flight,
             parent=parent
         )
diff --git a/qt_ui/models.py b/qt_ui/models.py
index bd0d6397..7155b3e0 100644
--- a/qt_ui/models.py
+++ b/qt_ui/models.py
@@ -100,6 +100,8 @@ class PackageModel(QAbstractListModel):
     #: Emitted when this package is being deleted from the ATO.
     deleted = Signal()
 
+    tot_changed = Signal()
+
     def __init__(self, package: Package) -> None:
         super().__init__()
         self.package = package
@@ -139,6 +141,8 @@ class PackageModel(QAbstractListModel):
         """Adds the given flight to the package."""
         self.beginInsertRows(QModelIndex(), self.rowCount(), self.rowCount())
         self.package.add_flight(flight)
+        # update_tot is not called here because the new flight does not have a
+        # flight plan yet. Will be called manually by the caller.
         self.endInsertRows()
 
     def delete_flight_at_index(self, index: QModelIndex) -> None:
@@ -155,14 +159,24 @@ class PackageModel(QAbstractListModel):
         self.beginRemoveRows(QModelIndex(), index, index)
         self.package.remove_flight(flight)
         self.endRemoveRows()
+        self.update_tot()
 
     def flight_at_index(self, index: QModelIndex) -> Flight:
         """Returns the flight located at the given index."""
         return self.package.flights[index.row()]
 
-    def update_tot(self, tot: datetime.timedelta) -> None:
+    def set_tot(self, tot: datetime.timedelta) -> None:
         self.package.time_over_target = tot
-        self.layoutChanged.emit()
+        self.update_tot()
+
+    def set_asap(self, asap: bool) -> None:
+        self.package.auto_asap = asap
+        self.update_tot()
+
+    def update_tot(self) -> None:
+        if self.package.auto_asap:
+            self.package.set_tot_asap()
+        self.tot_changed.emit()
 
     @property
     def mission_target(self) -> MissionTarget:
diff --git a/qt_ui/windows/mission/QEditFlightDialog.py b/qt_ui/windows/mission/QEditFlightDialog.py
index a3d8cbd2..a6893a47 100644
--- a/qt_ui/windows/mission/QEditFlightDialog.py
+++ b/qt_ui/windows/mission/QEditFlightDialog.py
@@ -4,9 +4,8 @@ from PySide2.QtWidgets import (
     QVBoxLayout,
 )
 
-from gen.ato import Package
 from gen.flights.flight import Flight
-from qt_ui.models import GameModel
+from qt_ui.models import GameModel, PackageModel
 from qt_ui.uiconstants import EVENT_ICONS
 from qt_ui.windows.GameUpdateSignal import GameUpdateSignal
 from qt_ui.windows.mission.flight.QFlightPlanner import QFlightPlanner
@@ -15,7 +14,8 @@ from qt_ui.windows.mission.flight.QFlightPlanner import QFlightPlanner
 class QEditFlightDialog(QDialog):
     """Dialog window for editing flight plans and loadouts."""
 
-    def __init__(self, game_model: GameModel, package: Package, flight: Flight, parent=None) -> None:
+    def __init__(self, game_model: GameModel, package_model: PackageModel,
+                 flight: Flight, parent=None) -> None:
         super().__init__(parent=parent)
 
         self.game_model = game_model
@@ -25,7 +25,8 @@ class QEditFlightDialog(QDialog):
 
         layout = QVBoxLayout()
 
-        self.flight_planner = QFlightPlanner(package, flight, game_model.game)
+        self.flight_planner = QFlightPlanner(package_model, flight,
+                                             game_model.game)
         layout.addWidget(self.flight_planner)
 
         self.setLayout(layout)
diff --git a/qt_ui/windows/mission/QPackageDialog.py b/qt_ui/windows/mission/QPackageDialog.py
index 2e78ce6e..10acc4fe 100644
--- a/qt_ui/windows/mission/QPackageDialog.py
+++ b/qt_ui/windows/mission/QPackageDialog.py
@@ -3,8 +3,9 @@ import logging
 from datetime import timedelta
 from typing import Optional
 
-from PySide2.QtCore import QItemSelection, QTime, Signal, Qt
+from PySide2.QtCore import QItemSelection, QTime, Qt, Signal
 from PySide2.QtWidgets import (
+    QCheckBox,
     QDialog,
     QHBoxLayout,
     QLabel,
@@ -15,16 +16,15 @@ from PySide2.QtWidgets import (
 )
 
 from game.game import Game
+from game.theater.missiontarget import MissionTarget
 from gen.ato import Package
 from gen.flights.flight import Flight
 from gen.flights.flightplan import FlightPlanBuilder, PlanningError
-from gen.flights.traveltime import TotEstimator
 from qt_ui.models import AtoModel, GameModel, PackageModel
 from qt_ui.uiconstants import EVENT_ICONS
 from qt_ui.widgets.ato import QFlightList
 from qt_ui.windows.GameUpdateSignal import GameUpdateSignal
 from qt_ui.windows.mission.flight.QFlightCreator import QFlightCreator
-from game.theater.missiontarget import MissionTarget
 
 
 class QPackageDialog(QDialog):
@@ -79,15 +79,17 @@ class QPackageDialog(QDialog):
         self.tot_spinner.setDisplayFormat("T+hh:mm:ss")
         self.tot_spinner.timeChanged.connect(self.save_tot)
         self.tot_spinner.setToolTip("Package TOT relative to mission TOT")
+        self.tot_spinner.setEnabled(not self.package_model.package.auto_asap)
         self.tot_column.addWidget(self.tot_spinner)
 
-        self.reset_tot_button = QPushButton("ASAP")
-        self.reset_tot_button.setToolTip(
+        self.auto_asap = QCheckBox("ASAP")
+        self.auto_asap.setToolTip(
             "Sets the package TOT to the earliest time that all flights can "
             "arrive at the target."
         )
-        self.reset_tot_button.clicked.connect(self.reset_tot)
-        self.tot_column.addWidget(self.reset_tot_button)    
+        self.auto_asap.setChecked(self.package_model.package.auto_asap)
+        self.auto_asap.toggled.connect(self.set_asap)
+        self.tot_column.addWidget(self.auto_asap)
 
         self.tot_help_label = QLabel("<a href=\"https://github.com/Khopa/dcs_liberation/wiki/Mission-planning\"><span style=\"color:#FFFFFF;\">Help</span></a>")
         self.tot_help_label.setAlignment(Qt.AlignCenter)
@@ -113,6 +115,8 @@ class QPackageDialog(QDialog):
         self.delete_flight_button.setEnabled(model.rowCount() > 0)
         self.button_layout.addWidget(self.delete_flight_button)
 
+        self.package_model.tot_changed.connect(self.update_tot)
+
         self.button_layout.addStretch()
 
         self.setLayout(self.layout)
@@ -145,14 +149,14 @@ class QPackageDialog(QDialog):
     def save_tot(self) -> None:
         time = self.tot_spinner.time()
         seconds = time.hour() * 3600 + time.minute() * 60 + time.second()
-        self.package_model.update_tot(timedelta(seconds=seconds))
+        self.package_model.set_tot(timedelta(seconds=seconds))
 
-    def reset_tot(self) -> None:
-        if not list(self.package_model.flights):
-            self.package_model.update_tot(timedelta())
-        else:
-            self.package_model.update_tot(
-                TotEstimator(self.package_model.package).earliest_tot())
+    def set_asap(self, checked: bool) -> None:
+        self.package_model.set_asap(checked)
+        self.tot_spinner.setEnabled(not self.package_model.package.auto_asap)
+        self.update_tot()
+
+    def update_tot(self) -> None:
         self.tot_spinner.setTime(self.tot_qtime())
 
     def on_selection_changed(self, selected: QItemSelection,
@@ -183,6 +187,7 @@ class QPackageDialog(QDialog):
             QMessageBox.critical(
                 self, "Could not create flight", str(ex), QMessageBox.Ok
             )
+        self.package_model.update_tot()
         # noinspection PyUnresolvedReferences
         self.package_changed.emit()
 
diff --git a/qt_ui/windows/mission/flight/QFlightPlanner.py b/qt_ui/windows/mission/flight/QFlightPlanner.py
index b4eb9b36..71904b48 100644
--- a/qt_ui/windows/mission/flight/QFlightPlanner.py
+++ b/qt_ui/windows/mission/flight/QFlightPlanner.py
@@ -1,9 +1,8 @@
-from PySide2.QtCore import Signal
 from PySide2.QtWidgets import QTabWidget
 
 from game import Game
-from gen.ato import Package
 from gen.flights.flight import Flight
+from qt_ui.models import PackageModel
 from qt_ui.windows.mission.flight.payload.QFlightPayloadTab import \
     QFlightPayloadTab
 from qt_ui.windows.mission.flight.settings.QGeneralFlightSettingsTab import \
@@ -14,22 +13,15 @@ from qt_ui.windows.mission.flight.waypoints.QFlightWaypointTab import \
 
 class QFlightPlanner(QTabWidget):
 
-    on_planned_flight_changed = Signal()
-
-    def __init__(self, package: Package, flight: Flight, game: Game):
+    def __init__(self, package_model: PackageModel, flight: Flight, game: Game):
         super().__init__()
 
         self.general_settings_tab = QGeneralFlightSettingsTab(
-            game, package, flight
+            game, package_model, flight
         )
-        # noinspection PyUnresolvedReferences
-        self.general_settings_tab.on_flight_settings_changed.connect(
-            lambda: self.on_planned_flight_changed.emit())
         self.payload_tab = QFlightPayloadTab(flight, game)
-        self.waypoint_tab = QFlightWaypointTab(game, package, flight)
-        # noinspection PyUnresolvedReferences
-        self.waypoint_tab.on_flight_changed.connect(
-            lambda: self.on_planned_flight_changed.emit())
+        self.waypoint_tab = QFlightWaypointTab(game, package_model.package,
+                                               flight)
         self.addTab(self.general_settings_tab, "General Flight settings")
         self.addTab(self.payload_tab, "Payload")
         self.addTab(self.waypoint_tab, "Waypoints")
diff --git a/qt_ui/windows/mission/flight/settings/QFlightDepartureDisplay.py b/qt_ui/windows/mission/flight/settings/QFlightDepartureDisplay.py
index 6d789585..fe1271ca 100644
--- a/qt_ui/windows/mission/flight/settings/QFlightDepartureDisplay.py
+++ b/qt_ui/windows/mission/flight/settings/QFlightDepartureDisplay.py
@@ -1,32 +1,38 @@
-import datetime
-
 from PySide2.QtWidgets import QLabel, QHBoxLayout, QGroupBox, QVBoxLayout
 
-from gen.ato import Package
 from gen.flights.flight import Flight
 from gen.flights.traveltime import TotEstimator
 
 
-# TODO: Remove?
+from qt_ui.models import PackageModel
+
+
 class QFlightDepartureDisplay(QGroupBox):
 
-    def __init__(self, package: Package, flight: Flight):
+    def __init__(self, package_model: PackageModel, flight: Flight):
         super().__init__("Departure")
+        self.package_model = package_model
+        self.flight = flight
 
         layout = QVBoxLayout()
 
         departure_row = QHBoxLayout()
         layout.addLayout(departure_row)
 
-        estimator = TotEstimator(package)
-        delay = estimator.mission_start_time(flight)
-
         departure_row.addWidget(QLabel(
             f"Departing from <b>{flight.from_cp.name}</b>"
         ))
-        departure_row.addWidget(QLabel(f"At T+{delay}"))
+        self.departure_time = QLabel()
+        self.package_model.tot_changed.connect(self.update_departure_time)
+        departure_row.addWidget(self.departure_time)
+        self.update_departure_time()
 
         layout.addWidget(QLabel("Determined based on the package TOT. Edit the "
                                 "package to adjust the TOT."))
 
         self.setLayout(layout)
+
+    def update_departure_time(self) -> None:
+        estimator = TotEstimator(self.package_model.package)
+        delay = estimator.mission_start_time(self.flight)
+        self.departure_time.setText(f"At T+{delay}")
diff --git a/qt_ui/windows/mission/flight/settings/QFlightSlotEditor.py b/qt_ui/windows/mission/flight/settings/QFlightSlotEditor.py
index d6e745e0..1ecb9a28 100644
--- a/qt_ui/windows/mission/flight/settings/QFlightSlotEditor.py
+++ b/qt_ui/windows/mission/flight/settings/QFlightSlotEditor.py
@@ -1,15 +1,20 @@
 import logging
 
 from PySide2.QtCore import Signal
-from PySide2.QtWidgets import QLabel, QHBoxLayout, QGroupBox, QSpinBox, QGridLayout
+from PySide2.QtWidgets import QLabel, QGroupBox, QSpinBox, QGridLayout
+
+from game import Game
+from gen.flights.flight import Flight
+from qt_ui.models import PackageModel
 
 
 class QFlightSlotEditor(QGroupBox):
 
     changed = Signal()
 
-    def __init__(self, flight, game):
-        super(QFlightSlotEditor, self).__init__("Slots")
+    def __init__(self, package_model: PackageModel, flight: Flight, game: Game):
+        super().__init__("Slots")
+        self.package_model = package_model
         self.flight = flight
         self.game = game
         self.inventory = self.game.aircraft_inventory.for_control_point(
@@ -70,6 +75,7 @@ class QFlightSlotEditor(QGroupBox):
     def _changed_client_count(self):
         self.flight.client_count = int(self.client_count_spinner.value())
         self._cap_client_count()
+        self.package_model.update_tot()
         self.changed.emit()
 
     def _cap_client_count(self):
diff --git a/qt_ui/windows/mission/flight/settings/QFlightStartType.py b/qt_ui/windows/mission/flight/settings/QFlightStartType.py
index 438c56de..b49fb5d7 100644
--- a/qt_ui/windows/mission/flight/settings/QFlightStartType.py
+++ b/qt_ui/windows/mission/flight/settings/QFlightStartType.py
@@ -1,14 +1,14 @@
-from PySide2.QtWidgets import QGroupBox, QHBoxLayout, QComboBox, QLabel
-from dcs.mission import StartType
+from PySide2.QtWidgets import QComboBox, QGroupBox, QHBoxLayout, QLabel
 
 from gen.flights.flight import Flight
+from qt_ui.models import PackageModel
 
 
 class QFlightStartType(QGroupBox):
 
-    def __init__(self, flight:Flight):
-        super(QFlightStartType, self).__init__()
-
+    def __init__(self, package_model: PackageModel, flight: Flight):
+        super().__init__()
+        self.package_model = package_model
         self.flight = flight
 
         self.layout = QHBoxLayout()
@@ -28,6 +28,4 @@ class QFlightStartType(QGroupBox):
     def _on_start_type_selected(self):
         selected = self.start_type.currentData()
         self.flight.start_type = selected
-
-
-
+        self.package_model.update_tot()
\ No newline at end of file
diff --git a/qt_ui/windows/mission/flight/settings/QGeneralFlightSettingsTab.py b/qt_ui/windows/mission/flight/settings/QGeneralFlightSettingsTab.py
index 71dfc036..5875a79d 100644
--- a/qt_ui/windows/mission/flight/settings/QGeneralFlightSettingsTab.py
+++ b/qt_ui/windows/mission/flight/settings/QGeneralFlightSettingsTab.py
@@ -1,9 +1,10 @@
 from PySide2.QtCore import Signal
-from PySide2.QtWidgets import QFrame, QGridLayout, QVBoxLayout, QLabel
+from PySide2.QtWidgets import QFrame, QGridLayout, QVBoxLayout
 
 from game import Game
 from gen.ato import Package
 from gen.flights.flight import Flight
+from qt_ui.models import PackageModel
 from qt_ui.windows.mission.flight.settings.QFlightDepartureDisplay import \
     QFlightDepartureDisplay
 from qt_ui.windows.mission.flight.settings.QFlightSlotEditor import \
@@ -19,14 +20,14 @@ from qt_ui.windows.mission.flight.settings.QCustomName import \
 class QGeneralFlightSettingsTab(QFrame):
     on_flight_settings_changed = Signal()
 
-    def __init__(self, game: Game, package: Package, flight: Flight):
+    def __init__(self, game: Game, package_model: PackageModel, flight: Flight):
         super().__init__()
 
         layout = QGridLayout()
         flight_info = QFlightTypeTaskInfo(flight)
-        flight_departure = QFlightDepartureDisplay(package, flight)
-        flight_slots = QFlightSlotEditor(flight, game)
-        flight_start_type = QFlightStartType(flight)
+        flight_departure = QFlightDepartureDisplay(package_model, flight)
+        flight_slots = QFlightSlotEditor(package_model, flight, game)
+        flight_start_type = QFlightStartType(package_model, flight)
         flight_custom_name = QFlightCustomName(flight)
         layout.addWidget(flight_info, 0, 0)
         layout.addWidget(flight_departure, 1, 0)
diff --git a/qt_ui/windows/mission/flight/waypoints/QFlightWaypointTab.py b/qt_ui/windows/mission/flight/waypoints/QFlightWaypointTab.py
index 92145a1c..abd1733d 100644
--- a/qt_ui/windows/mission/flight/waypoints/QFlightWaypointTab.py
+++ b/qt_ui/windows/mission/flight/waypoints/QFlightWaypointTab.py
@@ -29,8 +29,6 @@ from qt_ui.windows.mission.flight.waypoints \
 
 class QFlightWaypointTab(QFrame):
 
-    on_flight_changed = Signal()
-
     def __init__(self, game: Game, package: Package, flight: Flight):
         super(QFlightWaypointTab, self).__init__()
         self.game = game
@@ -163,4 +161,3 @@ class QFlightWaypointTab(QFrame):
 
     def on_change(self):
         self.flight_waypoint_list.update_list()
-        self.on_flight_changed.emit()