CORE allows you to track and accrue PTO with the HR subscription package. You can set the earning rules based on accrual in the Benefits screen. When you assign benefits to employees, their PTO is determined by that assignment.
When there are no benefits assigned to employees, PTO is determined by permissible hours set in their Employees profile. If you do not have a CORE HR subscription, you can just enter and track the Permissible Hours for PTO at the employee level. You can do this by entering PTO as a negative amount for each employee. Begin by setting the employee's permissible hours in the Employees > Employee Details > General > Dates & Hours screen. Then you can bank these hours as a negative time entry using your company's overhead project and a non-billable activity item (don't use GEN:COMP). Then run any employee PTO report to track time. If you log in a negative amount of PTO for everyone, CORE deducts from that amount when a PTO request is made.
If you want to track the available Personal Time Off (vacation and sick time), there is a dashboard widget named Paid Time Off and Comp Hours that allows you to see a summary of hours logged or used by employees against the sick, vacation, holiday and comp time activities within the specified date range. You can also track and see this information on the Personal Time Off Request screen (create and edit modes) info bar that summarizes the earned, used and available hours for the selected employee.