Hello @Natka,
I hope this message finds you well.
That is correct. You can only schedule changes with the Automation Plus Add-on.
As a workaround, you can create an attribute for the change date, and set up a reminder for yourself to change the Status. That way you will get notified when you need to change the status.
You do not need to overwrite the Hire Date if you do not want to. If you wish to keep the Hire Date from when the employee was External, you can keep it and just change the Status when you need to. This change will appear in the History tab of this employee with the date.
On the contrary, if you wish to change the Hire Date and have it reflect the date the employee became Internal, then you will have to change it manually on the day it happens. You can create a date attribute for that as well and set up a reminder.
I hope this helps!
Kindest regards,
Cécile.