In addition to tracking PTO, Built for Teams allows you to track unpaid time off. There are two ways to track unpaid time off:
Treating Unpaid Time Off on a Case by Case Basis
Most customers don't give employees a specific, pre-defined amount of unpaid time off to use each year. For most companies, unpaid time off is something of an exception, approved when necessary and only used occasionally by employees.
In this case, the best practice is to create an "unlimited" policy. Learn more about unlimited policies here.
Granting a Specific Amount of Unpaid Time Off
If your policy for unpaid time off specifies a specific maximum amount of unpaid time off an employee can use during the year, you'll want to create an "accrued and limited" policy, just like for your other paid time off policies.