The Salary consists of the following heads :-
1. Gross Payment 2. Deductions 3. Nett Payment.
If you take a leave, your Gross Salary will remain unchanged. The deductions on account of leave will be shown in the deduction head.
So, even if you take leave for full 30 days, your gross remuneration head will not change. Only the Deduction & Nett Payment Head will change.