All of our auto-refilling plans renew based on the initial time and date of your initial purchase!
For example, if you purchased a subscription at 8PM on the 13th of the month, new coins will be added to your account around 8PM on the 13th of the following month.
If your coins are delayed, check out this article for more information and how you can troubleshoot.
Note: You can keep track of when your plan refills via your coin deposit page. Read more about that here!