I realise this thread is old but I found a solution so I'd thought I'd post incase someone else like me stumbles upon this. So the answer is an app called "calengoo" it's a touch pricy £4.99 but totally worth it. Not only does it have fantastic google calendar integration and more settings and preferences than I can see anyone caring to configure, but it also can be used to completely manage the native calendar app! You can drag and drop appointments and then choose to either "move" or "copy" which is invaluable, if like me or some of the others in this thread you work irregular shifts. Also there are other neat features like template appointments, everything's already filled in just pick a start time and date. What's more all changes made in "calengoo" are instantly reflected in the native calendar app, no sync or Internet connection required. Down sides of the app are its not the prettiest app ever, the Ui is for lack of a better word, ugly. Also for your changes made in "calengoo" to be uploaded to iCloud you have to open the native calendar app after you have made changes, this isn't something they could fix however but a limitation imposed by apple. In conclusion if you want power user tools but want to stick with the native calendar app rather than move to google calendar then this is the app for you.