How to run an android function every 15 minutes , and specifically on the 15 minute mark everyday?

This maybe a repeated question here but I'm still facing issues on this, hope there's a solution around. Thanks in advance.

How do I set the alarm manager to run so as to execute the function specifically at every 15 minutes clock interval, for example 8:00, 8:15, 8:30, 8:45, 9:00 everyday regardless of the time when the application is started.

Take an example if let's say I started my application main activity at 7:47, and I would like the alarm to start at 8:00, followed along with 8:15, 8:30 and etc....how should I do? I would really appreciate if any suggestions are given..