Postpone the hire date when employee used unpaid leave

Summary

How can we postpone the employee's hire date when employee use unpaid leave?

Content

Hi,
As an example, let's say employee's hire date is 20.01.2019.
If employee use 10 unpaid absence, his hire date should be 30.01.2019 and the absence balance should be calculated according to this date anymore.

Is there any way to do that without using Fast Formula? I am looking for an configuration or some setup for this. (We are currently using Fast Formula and we had some exceptional situations. Because of that we are trying to think of ways to avoiding this.)

Thank you,
Best Regards,
Burakcan