Calendar apps are found throughout the Apple ecosystem in both iOS for mobile devices like the iPhone and in Mac OS X Mavericks for Mac computers. You can sync calendar apps through software or cloud systems so that the same events, details and alerts appear on both your Mac and iPhone. Sync calendar information stored locally on your computer to your iPhone through a wireless or USB connection via iTunes. Alternatively, automatically sync Web-based calendar services to your iPhone and Mac whenever they connect to Wi-Fi or cellular data.
You must complete an initial setup with a USB cable to enable future Wi-Fi syncing between your iPhone and Mac. Set up this feature by plugging in your iPhone to your Mac with the USB cable. Launch iTunes and click "Devices." Select the "Summary" tab and check the box next to "Sync with this iPhone over Wi-Fi," click "Done" and unplug your iPhone. Once you're ready to sync wirelessly, connect your iPhone and Mac to the same Wi-Fi network and plug in your iPhone to a power source. Launch iTunes, select "iPhone" and click on the "Info" tab. Check off "Sync Calendars" and press "Apply."
This syncing method requires no previous setup. Plug in your iPhone to your Mac with its USB cable. Launch iTunes and click on "iPhone" on the device toolbar. Select the "Info" tab and check off "Sync Calendars." Click "Apply" and wait until the progress bar shows that the sync is complete. Press the "Eject" button and unplug your iPhone.
If you have an Apple iCloud account, you can sync calendars with your Mac wirelessly from any location, without using iTunes. All your event information is stored on the iCloud Web server, and it is pushed to your iPhone and Mac through Wi-Fi or cellular data. Set up your iCloud calendar on your iPhone by opening the Settings menu and selecting "iCloud." Sign in to your iCloud account and switch on Calendars. Enable your iCloud calendar on your Mac by clicking the Apple menu icon on your system toolbar and selecting "System Preferences." Choose "iCloud" and sign in to your account. Check the box next to Calendars. Events added to the Calendar apps on your iPhone or Mac will automatically update across your devices.
Other Web-Based Calendar Services
ICloud is just one example of a Web-based calendar service. Many other free online calendars exist, such as Google Calendars, Yahoo, or Microsoft Exchange calendars. Add these accounts to your iPhone by opening the Settings menu and selecting "Mail, Contacts, Calendars." Tap "Add Account," select the third-party service and sign in. Set up these accounts on your Mac by launching the Calendar app, opening the program menu and choosing "Preferences." Navigate to the "Accounts" tab and click the "+" button. Select the third-party calendar service and sign in to your account. The events on this calendar service will automatically sync between your Mac and iPhone Calendar apps when your devices connect to the Internet.