Operating hours of an airport can be determined by checking the notams of that particular airfield. If no abnormal opening hours are mentioned there, there will be normal daytime flying and no night flying. Go to "www . notams . faa . gov", press "I agree", type the airfield's ICAO code in the top left text area and press "view notams" just below. A new screen will appear with all the active notams (notice to airman) of that airfield. The ICAO code for Norvenich is ETNN and the currently active notams show no extended opening hours, so no night flying. The only abnormality for the coming week is that the daytime operations will start 45 minutes later than normal, 8:45 local instead of 8:00. All times in the notams are zulu/GMT times. Add 2 hours for local times. I typed the FAA notam website link with additional spacings as it seems that I am not allowed to place any links in my messages yet, leave them out to get the correct web adres