Dear Kumar Gaurav,
Expenses relating to a particular financial year should be booked in that financial year itself.
With regards to your querry, the problem will arise only in the last month of the fnancial year. There also you have to pass an entry of salary already due i.e., from 26th of Feb to 25 th of March in the month of March and you also have to pass a journal entry with regards to salary for the rest of the period till 31st March (for 6 days). Since as per your querry salary is paid on 7th of next month. the salary for the period 26th feb to 25th march will be paid on 7th of April and salary of 6 days already booked in the month of march will be paid along with the salary of 25 days of April, on 7th of May.
In normal course of practice, no entry of 5 or 6 remaining days salary (as per your querry) is passed in books of accounts on month to month basis except at year end. But if you wish to do so, you can follow the above said procedure.