Scheduling and managing events using Outlook.com calendar
I had this issue with Outlook 2013. We had a company calendar created (as explained in the link:
About creating this calendar:
https://www.cogmotive.com/blog/office-365-tips/create-a-company-shared-calendar-in-office-365 )
Only the full days tasks were visible by other people who had this calendar in outlook added.
After all this, it seems that our problem is solved and all the modifications/additions of tasks made by the administrator of the calendar are visible to the other people in their outlook.
Thanks,
Teofil BOCANCEA