How to enable notification volume even when phone is silent?

[AC Question]

I have a DROID MAXX (Not RZR or MAXX 2). At night, I tend to keep my phone on vibrate. I have certain people set though so that if these important people call, then they will break the silent mode and I will hear it ring. I really liked this ability. However, I would also like if I could do this with specific application notifications as well. On my calendar app (the default one that comes on my phone), I can also have sound notifications for events, but when my phone is in vibrate or silent mode, these notifications only vibrate or are silent. I need these calendar events to be able to wake me up at 6:00 AM, so vibrate and silent mode don't cut it. But if I turn on the volume, then I also get sound for unimportant stuff like text messages, Facebook messages, and emails, none of which are urgent enough to wake me up that early in the morning. I would use an alarm, but my default alarm app isn't specific enough. I don't need to be woken up EVERY Tuesday, just the second and fourth Tuesdays of the month. My calendar app is able to provide notifications at these intervals, but like I said, won't bypass silent mode. Is there a setting in my phone that will allow this? Or is there an app (I would prefer a setting to an app, but if you know of an app please let me know)?