calculate the duration Month wise ( total days in to period wise )

Dear Friends,
I attached the excel file with this

In column C total duration ( this is total days calculated from B - A )

In Column D on wards the periods mentioned, if the usage falls on the period mentioned in columns that to be calculated in particular period

Please check for example in first row I put manual entry

Finally the value in Column C and Column P should match

Thanks, Please My description is not so good excuse for that, help me in this regard

Thanks again

Formula in post #2 can be shortened to this:

=IFERROR(1/(1/MAX(0,MIN(D$3,$B4)-MAX(D$2,$A4)+1)),"")

Thanks a lot genius ...... Thank you very much the problem solved

You're welcome. Happy to help.