Krishna,
Factory calendars can be maintained using transaction SCAL. No batch job is required to make Saturday and Sunday to be workdays.
For detailed info on the transaction, see the wiki page at http://wiki.sdn.sap.com/wiki/display/NWTech/SAP+Calendar+Master
This question has been asked and answered multiple times. Read the SCN rules of engagement at http://scn.sap.com/docs/DOC-19331 , where Rule 1 says
Search before you post to ensure your question, comment, blog, document and/or wiki page is unique and hasn’t already been asked, answered or covered.
Best Regards,
DB49