CalCopy

CalCopy let's you replicate calendars with the push of a button.
Select your source calendar, your target calendar, and specify a time span -- CalCopy will make sure the target calendar has exactly the same events in the specified time frame as the source calendar.

For example, CalCopy comes in handy if you have access to your company's business calendar from your (business) iPhone only and want to replicate it to another (private) calendar.

Note: the time span is restricted to roughly +/- 10 years. Ideally, you should only synchronize smaller time spans. In addition, be aware that iOS 12 adds new data security features which allow administrators of Exchange servers to restrict access to managed calendars.

If we may ask you a favor: in case you have questions or problems with CalCopy, please contact us first before leaving (possibly negative) feedback! We will do our best to help and resolve your problems -- but there is no technical way for us to help you or get in touch with you if you only leave feedback in the AppStore.