So, if I have to do a certain task during a whole week but with a 3-week gap. For instance, in a 3-week period I will have to do that task for 1 week, in a 6-week period for 2 weeks, not in a row, of course, and so on.
- One work week for each 3-weeks.
- Once in every 3-weeks.
Which is the best way to express this work schedule rotation?