SAP speedup searching sales documents

 http://it.toolbox.com/blogs/ehadzipetros/speeding-the-search-of-sales-documents-in-sap-33326

SAP ABAP HOW TO GET FISC YEAR FIRST DATE AND LAST DATE

To get first date and last date from fiscal year period (T009B), you can use this function module:
FIRST_AND_LAST_DAY_IN_YEAR_GET.

with 2 import parameters, the year and fiscal year variant.