Comment 3 for bug 1470583

It seems the "buggy" behaviour does NOT show up if one creates a new event and leaves the reminder time at it's default (15 min) !

It DOES (at least) show up if the reminder time is changed to 1 hour and 2 hours before (i tested just this two values).

Reproduce:

Open calendar
create new event by tapping "New Event"
set start time to something more than 2 hours from now
set reminder time to "2 hours"
wait...
Notification appears, sound rings 2 hours before event
2 minutes later
Notification appears, sound rings
.. and again..

Delete that event; notification stops.

Create new event by tapping "New Event"
set start time to something more than 15 minutes from now
leave reminder time at it's default (15 min)
wait...
Notification appears, sound rings 15 minutes before event.... just once!

My device:
BQ Aquaris E4.5 Ubuntu edition; device name: krillin / current build number: 23 / version version: 23