Hi Hasini,
You need to create the same cost center with validity period from 01.01.2013 to 31.12.2013. Through this method only you can pre-pone the validity of the cost center. Because you can only change account assignments, responsible persons, etc within the existing validity period by slicing the validity period into various analysis periods. You can't extend the validity period of the cost center by change function.
Sridhar