IV_BAND_CHG_DT1 is not returning grade change dates

Summary

IV_BAND_CHG_DT1 is not returning grade change dates

Content

We have defined a Accrual absence plan. Accrual Bands are defined based on the employee grades. We are trying to get the employee band changes(i.e. date from which the grade is changed there by change in the accrual band) using the IV_BAND_CHG_DT1 input of Global Absence Accrual Matrix formula. But IV_BAND_CHG_DT1 is not returning any dates. But the oracle documents says that it should return the date on which employee accrual band is changed. Please let know if we are missing any steps.