how to import a contact that is also an employee

When I import a contact that is also an employee, but the contact's hire date is before the employee's hire date, I get an error message that contact hire date cannot be before the employee's hire date.
I tried to change the date according to the employee's dates but I got another error message (attached).
how can i import a contact that is also an employee when the contact's ire date is before the employee's hire date he is associate to?