diff --git a/project.godot b/project.godot
index 4344570..e81f3ab 100644
--- a/project.godot
+++ b/project.godot
@@ -27,8 +27,9 @@ uuid="*res://addons/uuid/uuid.gd"
 
 [display]
 
-window/size/viewport_width=1080
-window/size/viewport_height=2340
+window/size/viewport_width=1920
+window/size/viewport_height=1000
+window/stretch/mode="viewport"
 window/stretch/aspect="keep_width"
 window/handheld/orientation=1
 
diff --git a/scenes/board/board.gd b/scenes/board/board.gd
index 31716e7..7eebb3d 100644
--- a/scenes/board/board.gd
+++ b/scenes/board/board.gd
@@ -5,7 +5,7 @@ const ReservationScene = preload("res://scenes/board/reservation.tscn")
 const ReservationIndent = preload("res://scenes/board/reservation_indent.tscn")
 
 const WorkingDayStart = 8
-const WorkingDayEnd = 21
+const WorkingDayEnd = 20
 
 const MinimalMinutesToShowTitle = 30
 
@@ -57,12 +57,12 @@ func _update_schedule():
 	var previous_finish_time = 0
 
 	for reservation in repo.list_reservations():
-		var start_time_hours = reservation.start_time['hours']
-		var start_time_minutes = reservation.start_time['minutes']
+		var start_time_hours = reservation.start_time.hours
+		var start_time_minutes = reservation.start_time.minutes
 		var start_time = (start_time_hours - WorkingDayStart)*60 + start_time_minutes
 
-		var finish_time_hours = reservation.finish_time['hours']
-		var finish_time_minutes = reservation.finish_time['minutes']
+		var finish_time_hours = reservation.finish_time.hours
+		var finish_time_minutes = reservation.finish_time.minutes
 		var finish_time = (finish_time_hours - WorkingDayStart)*60 + finish_time_minutes
 
 		var reservation_time = finish_time - start_time
diff --git a/scenes/common/error_box.gd b/scenes/common/error_box.gd
new file mode 100644
index 0000000..a90ba6a
--- /dev/null
+++ b/scenes/common/error_box.gd
@@ -0,0 +1,15 @@
+extends HBoxContainer
+
+@onready var _error_label := $ErrorLabel
+
+var _text : String
+
+func _ready():
+	set_message(String())
+
+func get_message() -> String:
+	return _text
+
+func set_message(value : String):
+	_error_label.text = _text
+	_error_label.text = value if value == "" else "❗ " + value
diff --git a/scenes/common/error_box.tscn b/scenes/common/error_box.tscn
new file mode 100644
index 0000000..514af89
--- /dev/null
+++ b/scenes/common/error_box.tscn
@@ -0,0 +1,19 @@
+[gd_scene load_steps=2 format=3 uid="uid://e73v63ysty2e"]
+
+[ext_resource type="Theme" uid="uid://cmhwbyqu6nh38" path="res://assets/themes/big.tres" id="1_bo38g"]
+
+[node name="ErrorBox" type="HBoxContainer"]
+
+[node name="Control" type="Control" parent="."]
+custom_minimum_size = Vector2(25, 0)
+layout_mode = 2
+
+[node name="ErrorLabel" type="Label" parent="."]
+layout_mode = 2
+size_flags_horizontal = 3
+theme = ExtResource("1_bo38g")
+theme_override_colors/font_color = Color(1, 0, 0, 1)
+theme_override_colors/font_outline_color = Color(0, 0, 0, 1)
+theme_override_constants/outline_size = 8
+text = "❗ Время начала не может быть больше времени окончания"
+autowrap_mode = 2
diff --git a/scenes/main/main_tablet.gd b/scenes/main/main_tablet.gd
index dddd325..427e77c 100644
--- a/scenes/main/main_tablet.gd
+++ b/scenes/main/main_tablet.gd
@@ -10,6 +10,11 @@ const BgColors = {
 }
 const MinutesForTemporarilyFree := 15
 
+enum Status {
+	FREE,
+	BUSY
+}
+
 @onready var _reservation_repo : AbstractReservationRepo = $Repos/Reservation
 
 @export var current_page : Pages:
@@ -36,6 +41,7 @@ const MinutesForTemporarilyFree := 15
 
 var _current_page := Pages.Board
 var _previous_page : Pages
+var _status : Status
 
 func _ready():
 	initialize_signals()
@@ -72,20 +78,24 @@ func _process_status(time):
 
 		if current_time_in_minutes >= start_time_in_minutes \
 		and current_time_in_minutes < finish_time_in_minutes:
+			_status = Status.BUSY
 			_status_label.text = "Занято"
 			_background.color = BgColors.busy
 			return
 
 		elif current_time_in_minutes <= start_time_in_minutes \
 		and current_time_in_minutes + MinutesForTemporarilyFree > start_time_in_minutes:
+			_status = Status.FREE
 			_status_label.text = "Свободно"
 			_background.color = BgColors.temporarily_free
 			return
 
 	if len(reservations) > 0:
+		_status = Status.FREE
 		_status_label.text = "Свободно"
 		_background.color = BgColors.free
 	else:
+		_status = Status.FREE
 		_status_label.text = "Свободно"
 		_background.color = BgColors.standart
 
@@ -119,6 +129,9 @@ func _get_time_status_indent():
 	return _time_status_indent.custom_minimum_size.y
 
 func _create_default_reservation(minutes_of_reservation):
+	if _status == Status.BUSY:
+		return
+
 	var datetime = Time.get_datetime_dict_from_system()
 	var start_time_in_minutes = datetime.hour * 60 + datetime.minute
 	var finish_time_in_minutes = start_time_in_minutes + minutes_of_reservation
diff --git a/scenes/main/main_tablet.tscn b/scenes/main/main_tablet.tscn
index 8fa9dcb..baddaf6 100644
--- a/scenes/main/main_tablet.tscn
+++ b/scenes/main/main_tablet.tscn
@@ -39,7 +39,7 @@ color = Color(0.133333, 0.14902, 0.176471, 1)
 layout_mode = 1
 anchors_preset = 9
 anchor_bottom = 1.0
-offset_right = 1576.0
+offset_right = 1781.0
 grow_vertical = 2
 
 [node name="Pages" type="BoxContainer" parent="Left"]
@@ -64,15 +64,18 @@ size_flags_horizontal = 3
 
 [node name="TimeStatusContainer" type="VBoxContainer" parent="Left"]
 layout_mode = 2
+size_flags_horizontal = 10
+size_flags_vertical = 0
 
 [node name="Indent" type="BoxContainer" parent="Left/TimeStatusContainer"]
-custom_minimum_size = Vector2(0, 206.667)
+custom_minimum_size = Vector2(0, 277.333)
 layout_mode = 2
+size_flags_vertical = 3
 
 [node name="TimeLabel" type="Label" parent="Left/TimeStatusContainer"]
 layout_mode = 2
 theme = ExtResource("5_atujq")
-text = "23:32"
+text = "17:52"
 horizontal_alignment = 1
 
 [node name="StatusLabel" type="Label" parent="Left/TimeStatusContainer"]
@@ -138,3 +141,17 @@ text = "Забронировать"
 
 [node name="Reservation" type="Node" parent="Repos"]
 script = ExtResource("5_6h0eq")
+
+[node name="DialogBox" type="VBoxContainer" parent="."]
+layout_mode = 1
+anchors_preset = 8
+anchor_left = 0.5
+anchor_top = 0.5
+anchor_right = 0.5
+anchor_bottom = 0.5
+offset_left = -20.0
+offset_top = -20.0
+offset_right = 20.0
+offset_bottom = 20.0
+grow_horizontal = 2
+grow_vertical = 2
diff --git a/scenes/reservation/reservation_creation.tscn b/scenes/reservation/reservation_creation.tscn
index eed60b6..7a60a40 100644
--- a/scenes/reservation/reservation_creation.tscn
+++ b/scenes/reservation/reservation_creation.tscn
@@ -1,8 +1,10 @@
-[gd_scene load_steps=7 format=3 uid="uid://csfn8q6b5hj4y"]
+[gd_scene load_steps=9 format=3 uid="uid://csfn8q6b5hj4y"]
 
 [ext_resource type="Theme" uid="uid://cmhwbyqu6nh38" path="res://assets/themes/big.tres" id="1_j1bkw"]
 [ext_resource type="Script" path="res://scenes/reservation/reservation_page.gd" id="1_prqr3"]
 [ext_resource type="PackedScene" uid="uid://d0fdiesiaajlq" path="res://scenes/common/edit_field.tscn" id="2_qfs8j"]
+[ext_resource type="PackedScene" uid="uid://e73v63ysty2e" path="res://scenes/common/error_box.tscn" id="4_ja64k"]
+[ext_resource type="Script" path="res://scenes/common/error_box.gd" id="5_bbsyh"]
 
 [sub_resource type="StyleBoxFlat" id="StyleBoxFlat_dlqbv"]
 bg_color = Color(0.6, 0.6, 0.6, 0)
@@ -120,6 +122,10 @@ custom_minimum_size = Vector2(0, 5)
 layout_mode = 2
 theme_override_styles/panel = SubResource("StyleBoxFlat_r7q2r")
 
+[node name="ErrorBox" parent="." instance=ExtResource("4_ja64k")]
+layout_mode = 2
+script = ExtResource("5_bbsyh")
+
 [node name="BottomBar" type="BoxContainer" parent="."]
 visible = false
 layout_mode = 2
diff --git a/scenes/reservation/reservation_edit.tscn b/scenes/reservation/reservation_edit.tscn
index e41d617..d953349 100644
--- a/scenes/reservation/reservation_edit.tscn
+++ b/scenes/reservation/reservation_edit.tscn
@@ -1,8 +1,10 @@
-[gd_scene load_steps=6 format=3 uid="uid://cu6e3hfdorwcg"]
+[gd_scene load_steps=8 format=3 uid="uid://cu6e3hfdorwcg"]
 
 [ext_resource type="Script" path="res://scenes/reservation/reservation_page.gd" id="1_81iob"]
 [ext_resource type="Theme" uid="uid://cmhwbyqu6nh38" path="res://assets/themes/big.tres" id="2_57fpn"]
 [ext_resource type="PackedScene" uid="uid://d0fdiesiaajlq" path="res://scenes/common/edit_field.tscn" id="3_lh5s8"]
+[ext_resource type="PackedScene" uid="uid://e73v63ysty2e" path="res://scenes/common/error_box.tscn" id="4_vg752"]
+[ext_resource type="Script" path="res://scenes/common/error_box.gd" id="5_xmu5c"]
 
 [sub_resource type="StyleBoxFlat" id="StyleBoxFlat_dlqbv"]
 bg_color = Color(0.6, 0.6, 0.6, 0)
@@ -115,6 +117,10 @@ custom_minimum_size = Vector2(0, 5)
 layout_mode = 2
 theme_override_styles/panel = SubResource("StyleBoxFlat_yafv8")
 
+[node name="ErrorBox" parent="." instance=ExtResource("4_vg752")]
+layout_mode = 2
+script = ExtResource("5_xmu5c")
+
 [node name="BottomBar" type="BoxContainer" parent="."]
 layout_mode = 2
 alignment = 2
diff --git a/scenes/reservation/reservation_page.gd b/scenes/reservation/reservation_page.gd
index a245140..825f14a 100644
--- a/scenes/reservation/reservation_page.gd
+++ b/scenes/reservation/reservation_page.gd
@@ -14,6 +14,7 @@ enum Types {
 @onready var _back_button := $TopBar/BackButton
 @onready var _apply_button := $TopBar/ApplyButton
 @onready var _delete_button := $BottomBar/DeleteButton
+@onready var _error_box := $ErrorBox
 
 @onready var _title_field := $TitleField
 @onready var _date_field := $DateField
@@ -25,6 +26,7 @@ enum Types {
 
 func _ready():
 	initialize_signals()
+	_error_box.set_message(String())
 
 func initialize_signals():
 	_back_button.pressed.connect(_on_back_button_pressed)
@@ -114,6 +116,7 @@ func _fields_are_correct():
 
 	if len(_title_field.get_value()) < 1:
 		print("The title is not entered.")
+		_error_box.set_message("Не введено название встречи")
 		successful = false
 
 	if not _time_is_correct():
@@ -125,6 +128,14 @@ func _time_is_correct():
 	var start_time = _start_time_field.get_value()
 	var finish_time = _finish_time_field.get_value()
 
+	var time_is_not_entered = \
+		start_time["hours"] == 0 and start_time["minutes"] == 0 or \
+		finish_time["hours"] == 0 and finish_time["minutes"] == 0
+
+	if time_is_not_entered:
+		_error_box.set_message("Введите время начала и окончания встречи")
+		return false
+
 	var start_time_is_after_finish_time = \
 		start_time["hours"] > finish_time["hours"] or \
 		(start_time["hours"] == finish_time["hours"] and \
@@ -132,6 +143,7 @@ func _time_is_correct():
 
 	if start_time_is_after_finish_time:
 		print("Start time should not be more than or equal to finish time.")
+		_error_box.set_message("Время начала не может быть больше времени окончания")
 		return false
 
 	var repo = _main.get_reservation_repo()
@@ -168,6 +180,7 @@ func _time_is_correct():
 
 		if is_busy:
 			print("The selected time slot is busy.")
+			_error_box.set_message("Выбранный временной интервал занят")
 			return false
 
 	return true