Why can't I skip weekends for time estimates?
Skip weekends can only be used in workspaces where all users share the same workweek settings (e.g., week starts on Monday).
The reason is simple - to make sure everyone in the workspace has the same information. Otherwise, if the weekends vary, your team members could be looking at different time estimations that what you've set up.
What can you do?
If you wish to start using the skip weekends functionality, coordinate and agree to use the same weekend settings with your team.
Weekend settings can be found under everyone's profile settings.