Modify Personalized Cron Settings to follow drupal's timezone settings

Hello,

First, I would like to say thank you for sharing this module. This helped me with a recent project where I had to schedule a specific cron task to run daily at exactly 12mn, Europe/Paris time.

The only issue I had with this is that the personalized cron setting for this cron job had to be based on the server's timezone (America/Denver). Denver is 8hrs behind Paris so instead of putting 0 0 * * * for the cron job, I had to put 0 16 * * * so that it runs exactly at midnight in Paris time.

The problem is that looking at these settings, it doesn't make sense to a user and it does not match Drupal's default date timezone setting so it's confusing. Furthermore, this currently works in one server but once the site is deployed to another server, we will need to change the settings again.

I would really appreciate it if you could have a look at this. Thanks.