Notification by mail in php

I am doing a project for my campus, here the teacher assigns assignments to complete with a deadline date for students to complete, what I want is, 1.on button click(assignment doc upload by faculty) it should notify the students by mail whose email ids are stored in database. 2.automatically notify by mail to students one day before deadline from server as tomorrow is the last date.

I am coding in php, using wamp server with phpmyadmin, mysql, in notepad++.........

A brief idea I got is on code like fetching the db mail list in variable, then sending mail all at once as bcc, using mail ($ to, $ subject, $ message) however I havent checked it because I dont knw whether to implement just by code or use something els like cronos n etc. Plz help. Thank you.