If your absence screen is showing incorrect dates for the absence period, you need to check the following:
Employment start date: If you started mid-period, your leave period dates range from the employment start date to absence period end date.
Salary effective date: first salary line.
Holiday Entitlement effective date.
Continuous service date: This can sometimes be used to start the employee's holiday entitlement depending on your configuration.
Contract end date: If an employee has a contract end date entered, this can cause the leave period to range from absence period start date to contract end date and may result in a past date.