Factory calendar error in service order

Dear Guru's

could any body help me in solving the below issue.i created the service notification in iw51 after that i clicked the service order tab then system gives the pop up mesage in that i mentioned order type,planning plant,business area,main work center after that i got the below error.

Date 09.09.2011 is after the valid factory calendar period

Message no. IW432

Diagnosis

You entered a date for which the factory calendar was not maintained in your factory.

System Response

Processing will not be continued.

Procedure

Enter a valid date.

If you want to use the date rejected by the system as a valid date, you must maintain the factory calendar in your system with the help of the Customizing function:

Proceed

If you are not allowed to perform the function, contact your system administrator.

from which master data system is picking the Factory calendar.

how to solve the problem.

Thank you in advance.

suribabu.