I think deletion is not the Best Option, I am sure the better Option is "hide" duplicates as you might not be able to really delete in other people calendars.

Therefore Please also See the other voted idea named "Combine calendar items with same name from different calendars" about combining Events at least for the view/widgets to ease up the view by not showing exact duplicates...

Yes, I would also find this very useful. I also agree with the criteria: same day + same time + same description.

Vote! I have multiple accounts/calendars added and some events are shared creating multiple entries. It would be great if there was an option to hide duplicates

I have an interesting situation in that I have multiple emoloyee's outlook calendars linked. Unfortunately several of them have our internal 'office calendar' on their outlook-leaving me with 8-9 duplicates of a particular event.
Is there a current time way to mass delete duplicate events? 

It would be nice if the app could auto-detect duplicate events such as birthdays or anniversaries that show up from several different sources (facebook, other calendar apps, phone contacts, etc.) Not all of my events are from the same source app. Some birthdays are in my phone, some in Facebook, some just in your calendar app. So i dont want to turn off viewing one (like Facebook) as i may miss a birthday that only shows up there. However, if i keep them all viewable, i see multiples of the same event from all sources.
Hopefully this can be fixed in future updates? Love the app! Even purchased the pro version! 

Thanks!

Add a function (checkbox) to check for duplicate entries in calendar. Same day, time and description.
Then delete duplicates.

Sometimes when working with multiple calendars, there can be duplicate events, such as holidays or birthdays. Other time management software I've used has filtered these and only displayed one in the widget. This would be a nice feature to add to Business Calendar. Thank you all for a great app! I use it heavily.