RE:RE:RE:Mayor, I know I should not be concerned, but here this is for you and Manxcan that don't understand the methodology on when the contract ends.
https://www.cmegroup.com/trading/energy/natural-gas/natural-gas_product_calendar_futures.html
Trading of any delivery month shall cease three (3) business days prior to the first day of the delivery month. In the event that the official Exchange holiday schedule changes subsequent to the listing of a Natural Gas futures, the originally listed expiration date shall remain in effect. In the event that the originally listed expiration day is declared a holiday, expiration will move to the business day immediately prior.