Hello Eswar,
Planning calendar Date depend on the Factory calendar dates, and if factory calendar has non working day and same day period start date fall in that case Planning calendar consider the period date as per planning calendar calculation rule selection.
Ex. 1. do not displace, 2. Previous working day 3. Previous working day 4. No new period.
Please check the document for detail functionality of calculation rule.
There is no additional rule available to block the date in planning calendar. You can select the planning calendar rule as per your requirement and calculate the period.
In your planning calendar case, you have set as every Monday calculation rule and delivery date set as Period end date.
Please remove the all period firmed indicator in your planning calendar (Yellow marked) and save the changes
Again go to change mode and with proper selection of the date and execute the period calculation.
It will show all the correct period.
Please follow the above step and share the details.
Regards
Umesh Mali