Indicator Crash on CalDAV entry without time set

[Leso_KN]

First of all, sorry; this explanation got a little long, but i fixed the bug myself for now. This is just a description for the developers, to fix the bug in the future.

A brief explanation what "without time set" is supposed to mean:

Let's say you synchronize your reminders from your phone over icloud (as i do - caldav.icloud.com)
then there may be reminders that are not triggered by time, but for example by a location.

I recently set a reminder to occure when i enter a specific street.
As i went to that street these days the reminder came up on both devices, my phone and the ubuntu machine.

Of course i did only set the location where the reminder should occure, no additional time.

But as the reminder got triggered and was shown on the ubuntu machine, there simply was a notification in the top right corner saying "[Reminder info] (Invalid time: 0 seconds ago)

Later i noticed, that the clock in the unity bar had frozen some time ago.

I tried serval things and tried every known solution i could find - still nothing.

Everything that happened was: when i restarted whole unity, the time was uptodate (for that moment) and the service was active for half a second, then it crashed, i could not access any menu entries from the clock menu, neither change the time settings.

I started the indicator-datetime-service from command line, it simply crashed and now the clock also disappeared, only appearing for a second on launching the service again.

The bug could be fixed by opening the synchronized calendar in Evolution and removing the concerning reminder. I could then launch the service again and my time is now uptodate.

I guess this is something not occuring very often, but i think it should probably fixed so that a reminder without time set doesn't crash the whole service.

Additional info:

Package: indicator-datetime
Version: 15.10+16.04.20160406-0ubuntu1

Ubuntu Version 16.04.1 LTS 64bit

To reconstruct the bug: Use any calendar software (Evolution for example)
                        to connect to a caldav calendar that supports different triggers than
                        time (iOS reminders app for example - supports setting a
                        place as trigger)
                        Set the default calendar application to the ubuntu system internal one
                        (gnome-calendar) and check if the calendar appears there as well
                        Then on the other device / software, that supports the different trigger,
                        simply add a reminder triggered not by time, but by that other event and
                        fire it.
                        The bug should now occure, the clock should freeze and the service should
                        crash.

[Leso_KN (leso-kn)]

I excuse for the bad formatting in the end