SAP Steps for Opening previous period in MM

If you want to open previous period for reversal entry or additional entry
The following are steps for Opening previous period in MM :
1. Go to TCode SU01 (see OSS NOTES 487381)
2. Choose "change" tab with your loging Name
3. Choose "Parameter" tab and give Parameters MMPI_READ_NOTE with date format as YYYYMMDD
4. SAVE.
5. Go to T-code MMPI
6. open the old periods which you want to post into
Note : the period opening will be valid for only for the particular day only.
7. Complete the posting you want to reverse or add
8. Go to MMPV to close the periods
Note : If we enter the date or month in MMPV means we are opening that date or month by closing previous date or month (Never use MMPV without completing the transaction in previous month)