Originally Posted by
TED74
If your base/aircraft is awarded an additional supp day (or two) in the annual sick leave use contest, you also get one (or two) additional IVD occurrences in the year. IIRC, there’s no obvious way icrew displays this potential to you so you just have to track it yourself.
This isn’t quite true. Your category will get supplemental vacation days added onto a week of vacation. You can then use those days to be converted into IVDs without affecting your base week of vacation, but no matter what you can still only use IVDs twice a year with up to 4 combined total days of usage.