Step 1. Connect your iPhone and scan
After running iPhone Data Recovery program, connect your iPhone to the computer via USB cable. Remember not to start iTunes in this way. The program will automatically detect your iPhone when it connected. Then the main window comes out as below. Then click the button "Start Scan".
Step 2. Preview the files on your iPhone
After a few minutes for scanning, all found data on your iPhone will be displayed in categories. You can choose "Calendar" to preview and check them in detail.
Step 3. Restore calendar on iPhone
Select the calendar that you need and press the button "Recover" to save them on your computer.
Step 1. Scan and extract iTunes backup file
Run the program and turn to the mode "Recover from iTunes Backup File" on the primary window. Then you will see all your iTunes backup file listed on the frame. Select the one for your iPhone. Just click "Start Scan" to extract the iTunes backup file.
Step 2. Recover iPhone calendar from iTunes backup file
When completed, you can preview all the data on your iTunes backup file. Tick the category "Calendars" and check the item one by one. Then choose the iPhone calendars you want to keep and restore them on your computer by clicking "Recover".
Step 1. Log in your iCloud account
Launch iPhone Data Recovery program and move to "Recover from iCloud Backup File". Sign in to your iCloud account by typing your Apple ID and password.
Step 2. Download the iCloud backup for your calendar
After entering in your iCloud account, you will see all the iCould backup file. Choose the one including your calendar and click "Download" to download it.
Step 3. Preview and recover deleted calendar
After download, all the data in the iCloud backup file will shown on the window. Preview the "Calendars", mark the items you desire and click "Recover". The deleted calendar on iPhone will be extracted on your computer as you expect.