Generally staff are unable to view unpublished rosters (refer: Why can't employees see future rostered shifts?) however, if staff are able to view rosters that have not been published permissions in access levels will need to be updated.
Unpublished shifts in Humanforce
Unpublished shifts in Roster Summary will show a blue icon under the shift times.
These same icons will show in the Rosters option in the Employee menu
To change this setting, click on Setup > Access Levels
Select the Access Level Name you wish to edit, eg: Employee
Click on the Permission tab > expand TimeTarget Online > scroll down to View Roster Page
Untick View Unpublished Rosters