Crew Change Calendar is a small app that is used by people working even time rotations. Such rotations would be 28/28, 21/21, 14/14 days to name a couple.
The layout of the app inputs is as follows: Starting date: is the start date actually being on the job. Days before: is how many days before your start date do you leave for work. Days after: is how many days after the hitch do you start for home. Duration of Change: is how many days do you work on the job. 2 x Duration: covers the days working and the time off. An example for this would be, doing a 28/28 rotation the Duration would be 28 x 2.