Service tax entries in GL getting generated on Invoice date basis

Hi Experts,

    Service tax entries in GL are getting imported on Invoice date basis instead of GL date basis

Case : AP  Invoice date: 1-Sep-15

          AP GL date: 1-Apr-16

Used RCM service tax, on running service tax processor and importing the same in GL the entries are getting generated on Sep-15 period instead of Apr-16 period, please guide

Thanks,