As an ATP Pilot (Score 1)

As an Airline Transport pilot I can tell you this is very common and a normal occurrence. I can assure you we know the difference between magnetic north and true north, and we know which one to use when. Additionally when we are flight planning we use true north corrected to magnetic north. Our maps (sectionals, WAC charts etc.) provide "isogonic lines" which tell us what to subtract or add to get to magnetic north, additionally we need to account for winds, and any compass error.