How to schedule dynamic function with cron job?

Question

I want to know how I can schedule a dynamic(auto populated data) function to auto run everyday at saved time?

Let\'s say I have a form that once the button is clicke

Answer 1

Cron tasks require you to preset the times at which they run, they cannot (yes you could hack this by having a script which edits your crontab, but I would not say that is a very good idea) have their time to run decided dynamically. This means you essentially have two options:

1) Set a cronjob to run every minute and use a temp file which you touch to tell the last time that it ran one of the scheduled tasks Each time that it runs it checks if there was a task to run in between the last timestamp of your temp file and the current time, and if there is it runs the task. This is a gross but simple solution.

2) Don't use cron. Create a daemon which checks what times tasks need to be run and puts them into a priority queue, then it pops the earliest element and sleeps until it is time to run that task. It runs the task and reinserts it to be run 24 hours in the future and repeats. This solution is by far more elegant, but it also requires more work.