How to Open and Close Periods in Posting Period Variant

Enter the Transaction Code S_ALR_87003642 in the SAP Command Field

In the next screen, Position the Variant you want to maintain and account type for which you want to open or close the periods.

Change the period , with following steps

1. Select Posting Period Variant
2. Select Account Type
3. Enter the Account number range for which you want to change the periods
4. Enter the Period to Open as per the Fiscal Year Variant of the Company Code assigned to the Posting Period Variant.
5. Enter the Period to which posting to be Open
6. Enter Any Special Period you want to Open 

All Other periods will remain close for posting for the Account range mentioned

After maintaining the periods, Press 'Save' from the SAP Standard Toolbar

In the next screen , Enter the customizing request number

You have successfully maintained periods in Posting Period Variant