Added a game timer and put it on the game manager to handle day end events

scenes/game_manager.tscn

@@ -4,3 +4,25 @@
 
 [node name="game_manager" type="Node"]
 script = ExtResource( 1 )
+
+[node name="UI" type="Control" parent="."]
+anchor_right = 1.0
+anchor_bottom = 1.0
+rect_pivot_offset = Vector2( 1024, 600 )
+
+[node name="day_timer_text" type="Label" parent="UI"]
+unique_name_in_owner = true
+anchor_left = 0.752
+anchor_right = 0.808
+anchor_bottom = 0.016
+margin_left = -67.8719
+margin_right = -68.5601
+margin_bottom = 0.199999
+rect_scale = Vector2( 5, 5 )
+text = "Time Left: "
+uppercase = true
+
+[node name="day_timer" type="Timer" parent="."]
+unique_name_in_owner = true
+
+[connection signal="timeout" from="day_timer" to="." method="_on_day_timer_timeout"]