Resignation Date Confusion: Is the Submission Date the Start of the Notice Period?

If any candidate submits his resignation letter on a particular date, will that date be considered his resignation or notice date?

Please suggest.

The letter of resignation also amounts to notice, and there is no need for a separate notice to be given. Many times, the resigning employee provides the date when they would like to be relieved, so the notice given is clearly calculable. Where the employee wishes to be relieved immediately, it means there is no notice, and the notice period pay can be recovered.