Available / unused time slots are shown in green only for admins. They are invisible to non-admins viewing your schedule.
You can hide them from your view (and show them again) using the toggle button at the top of the schedule:
If you'd like to completely get rid of these free slots, you can click the trash can in the note at the top of your schedule maker:
Show or hide free slots on public schedule
You can control whether to show or hide your unused time slots on the public schedule via the corresponding toggle under Settings on the Schedule Maker:
