Cron Job on selected time by user
Let me explain in detail:
There are 5 options:
1. 3 Minutes
2. 5 Minutes
3. 15 Minutes
4. 30 Minutes
5. 1 Hour
If user selects time 3 minute, After every 3 minutes script should run and if response is false, through an email to user.
So every user will have different time, how to control this?