A BYE for a team means that team has no game on a given date. Typically BYEs occur when there are an odd number of teams in a division. Once a schedule is made and saved, sometime it is necessary to edit or add a BYE.
To do this, go to the division schedule page, and click on Edit Bye next to a listed BYE to change the team or delete it. Click on Add a Bye to add a bye to a given date.