How to send email after 1 month with php

In my web-application, i want to create a some-type of calendar plus reminder. For example, i need to create task and i want to receive a e-mail notification after 1 month.

How to implement it?

Thanks in ad开发者_运维问答vance.

---

Have a cron job run every hour or so that finds all messages that haven't been delivered that were created a month ago.