Originally Posted by
Whoopsmybad
Yes one day of IVD can drop any length of trip. Just remember that you only have 4 (6 if you get 3 weeks of vacay) and can only do it twice. The big awesomeness is to get 2 trips back to back and use one instance to drop 2 trips.
If your base+aircraft wins the sick leave contest, you get one or two more IVDs AND corresponding additional one or two more INSTANCES.