Encounter Available PTO Bal. for Future Date

It will be helpful if Appogee can calculate the future available PTO bal. when employee requests PTO in future date. 

For example, employee A earns 10 hours per month, and he has 20 hours PTO as of 05/31/18. On 05/31/18,  employee requested PTO for 24 hours for 06/28/18-06/30/18. It will be nice if Appogee can calculate employee A's potential PTO Bal. as of 06/30/18, showing he has 30 PTO hours as of 06/30/18