When editing Control Tower Hours field you can choose the timezone for opening hours between Local Time (LT) and UTC (Z). The zone highlighted blue is the zone that applies to Opening Hours.
This does not mean that Leon will recalculate times in this section of Airport Directory.
Airport opening times will be checked when adding a flight based on the information in this section.
When the flight is scheduled to take off or land outside permitted hours the following message will display: Departure (Destination) airport is closed at the time of departure (arrival)