Well, duh, found the setting in Calendar. Changed it to from status bar notification to alert and set reminder time 5 minutees. All it did was display a big calendar icon and minimal information on the lockscreen if I turned the display on right after the alert sound. If you turn the display on later, there's no indication of the event reminder on the lockscreen anymore (clears by itself.) Furthermore, the 5 minute reminder didn't work, 5, then 10 minutes later no sound, vibration nothing and I made sure to do nothing with the phone when I added the second test even and the initial alert came through.
This is a disappointing area of Android. I would have expected better. Hello Pure Calendar Widget (Agenda) and Calendar Snooze.
By the way, Hadron, you're the man. Thanks for all your posts. I hope someone is paying you to answer all these newbies questions like me. It sure is helping a picky user like me transition from iOS to Android a lot quicker. One of the benefits maybe in general of the Android "community" - lots of "power users" willing to help others.