Q: ipad air calender not syncing with iphone 5s calender

Howdy andyq180,

Thanks for using the Apple Support Communities.

From your post I see that your iPad is not able to sync the iCloud calendar content from either iCloud.com or your other iOS device.  To troubleshoot this, please follow the steps outlined below.

Troubleshooting on iOS devices

First, confirm that you've turned on iCloud Calendar by tapping Settings > iCloud on your iPhone, iPad, or iPod touch, then check that Calendars is turned on.

If you are having trouble with the Calendar app on an iOS device (iPhone, iPad, or iPod touch) and iCloud Calendar, try these steps, testing after each to see if the issue is resolved.

• Make sure you've updated to iOS 5 or later. If your issue isn't resolved, try installing the latest version of iOS supported by your device. For instructions on setting up iOS for iCloud, see iCloud Setup.
• Make sure your iOS device is online. Attempt to view www.apple.com in Safari. If you can't connect to the Internet, your iCloud calendars and events will not update in your Calendar application. Learn how to troubleshoot your Internet connection.
• Open a secure website to test if ports 80 and 443 are accessible. Calendar requires port 443 access to iCloud to push and fetch updates to and from the iCloud Calendar servers.
• If recent changes don't appear, try to refresh your calendars:
  • In iOS 7, open Calendar and tap the Calendars tab to load the Calendars list, then pull down on the list to refresh.
  • In iOS 6 or iOS 5, open Calendar and tap Calendars in the top-left corner to load the Calendars list. Then tap the Refresh button in the lower-left corner of the Calendars list window.
• If you've recently made changes to your contacts' birthdays and are not seeing those changes reflected in your Birthdays Calendar, try to refresh your calendars. If you made the changes in the Contacts app on your Mac or at iCloud.com, it may take up to an hour for those changes to appear on your other devices.
• If you add new events on your iOS device, but they do not update on iCloud.com or your other devices, confirm that you've added the event to an iCloud calendar:
  • In iOS 7, open Calendar and tap the event to view the Event Details. Tap the calendar name to confirm that you've saved the event to an iCloud calendar.
  • In iOS 6 or iOS 5, open Calendar and tap the event to view the Event Details. Tap Edit > Calendar to confirm that you've saved the event to an iCloud calendar.
  • You may want to verify your default calendar settings. If you want to create new events in an iCloud calendar, set that calendar to be your default calendar. You can modify Default Calendar settings in Settings > Mail, Contacts, Calendars > Default Calendar.
• If you're using iOS 7, quit and restart the Calendar app:
  1. Press the Home button twice to see preview screens of the apps you have open.
  2. Find the Calendar preview screen and swipe it up and out of preview to quit the application.
  3. Tap the Home button to return to your Home screen.
  4. Wait a minute before reopening the Calendar app.
• If you're using iOS 6 or iOS 5, quit and restart the Calendar app:
  1. Press the Home button.
  2. Double-click the Home button to open the multitasking menu.
  3. Tap and hold the Calendar icon until it jiggles.
  4. Tap the "X" to remove Calendar from the list.
  5. Press the Home button to go back to your Home screen. Wait a minute before reopening the Calendar app.
• Restart your iOS device: Hold down the Sleep/Wake button until the red slider appears, then drag the slider. After the device turns off, turn it back on by pressing the Sleep/Wake button until the Apple logo appears. This may sound simple, but it reinitializes your network and application settings and can frequently resolve issues.
• Change the Sync settings for your calendars:
  1. Tap Settings > Mail, Contacts, Calendars.
  2. Under Calendars, tap Sync. If Sync is set to All Events, set it to a specific duration, such as Events 1 Month Back. If it's already set to a specific duration, set it to All Events.
  3. Tap the Home button. Wait several minutes, then open Calendar and try to refresh your calendars again.
• Turn iCloud Calendar off and back on:
  1. Tap Settings > iCloud.
  2. Turn off Calendar. Choose to delete data only if your data exists at icloud.com/calendar or on one or more of your computers. Otherwise, choose Keep Data.
  3. Wait a few minutes before turning Calendar back on.

iCloud: Troubleshooting iCloud Calendar - Apple Support

Take care,

Alex H.