How To Mark Events On Iphone Calendar

Apple Mac, iPad or iPhone calendar not syncing? Take a look at our easy to follow guide to get this fixed.

We all lead busy lives and many of us depend on our paper diary or smartphone calendar apps to keep track of our schedule.

Many of our Apple-based customers use the built-in Calendar app in macOS, iPhone and iPad.

Keeping your calendar in sync between devices should be easy, but there's a lot of reasons it might go wrong. Here we explain some of the more common causes of calendar events not syncing between iPhone, iPad and Mac.

The Fundamentals Of Calendar Sync

It first helps to understand the very basics of what's happening when we sync calendars.

You will likely have at least one service provider account on your device. These accounts keep your calendars in sync.

Most commonly, the service provider will be Apple iCloud, Microsoft Exchange and/or Google Calendar. Other lesser-known providers may use something called CalDAV, which is essentially the same thing.

Any of these systems are designed to sync calendars between your phone, tablet and computer.

In order to maintain an up-to-date calendar, the devices themselves must send any calendar changes to the service provider. Your other devices can then periodically check with the same service provider, to see if any changes were made, in order to keep themselves up-to-date.

So, what are the most common issues?

1 – The device or account is offline

This is always the first check.

Any kind of warning, password popup or exclamation mark on your calendar app indicates some issue with your device communicating with the service provider. This means it won't be able to send or receive any calendar event changes and will therefore fall out of sync.

Start by checking your internet connection is online. The easiest way for most users to check their internet connection is to try loading up any website. A particularly good test is to perform a Google search for something very random, that way you know that the browser isn't loading up a previously-saved page and must therefore have internet access.

If you definitely have internet access, restart your Mac from the Apple menu (top left of screen) > Restart. If you're on iPhone or iPad, shut it down and restart. This sounds like overkill, but it guarantees your Calendar app has been fully quit and reopened, as it's easy for inexperienced users to simply close the window and not fully quit the app.

After restarting the device, check whether the calendar account is no longer showing any warnings, or prompting for passwords.

If your account password is being refused or is incorrect, you may need to reset it by contacting the relevant service provider.

Refer to our article "6 Reasons Apple Mail Keeps Asking For A Password", as the guidance in there for resetting an email password is equally relevant to calendar syncing accounts, too.

2 – You saved a calendar event in a different account

At the start we mentioned several types of calendar service provider. Many people will have at least one of these account types on their device, usually two or more.

Let's say you have an iCloud and a Google account set up on your iPhone and iPad.

You create a new event in your Google calendar on your iPhone, and it syncs to the iPad no problem. But maybe you only set up iCloud on your Mac, and not the Google account too. You're not going to see the new event until you set up the Google account on your Mac.

This scenario might be extra puzzling because you do have iCloud on all 3 devices. So if on the previous day you unwittingly added a new event to your iCloud calendar, it would have synced to all 3 devices without any apparent problems.

This multi-account situation causes all kinds of confusion and headaches for users who simply don't realise or understand where (i.e under what account) they are actually saving their calendar data. It effectively causes your calendar data to become split between multiple service providers.

As such, it pays to have a clear understanding of what accounts you have signed into on your devices, and which of those accounts are able to sync calendars.

Our usual advice to most users is aim to only have one account enabled for calendar syncing, to avoid any confusion. At most, you might want two; one for work, one for personal. But then you need to be 100% confident in exactly how to save new calendar events in the correct account, and both accounts must be set up on all your devices.

To check what accounts you have active at the moment:

macOS (Mac)	Apple menu (top left) > System Preferences > Internet Accounts	Check which accounts have "Calendars" as an option and which ones are ticked.
iPadOS and iOS (iPad and iPhone)	Settings app > Calendars > Accounts	Tap each account in turn and check which ones have "Calendars" as an option, and which ones have that function switched on.

3 – You haven't enabled a sub-calendar

Many Calendar apps allow you to set up several sub-calendars for different purposes. A common example is having a separate work and home calendar, but you might have one for holidays or other categories. Often you can colour those events separately to help you stay organised.

Remember that we can also have multiple calendar service providers. Each of those service provider accounts might have several sub-calendars. So very quickly, this can get confusing.

If a calendar account is properly in-sync between all devices, you should see every one of your sub-calendars on every device. On the Mac it's usually quite clear to see which calendars are enabled by looking in the left sidebar, or by clicking the Calendars button in the top left. But on the iPhone or iPad you must, usually, tap the Calendars button to see which sub-calendars you have 'ticked' at any time.

The idea is that you can deselect ("un-tick") individual sub-calendars, to help reduce clutter in a busy calendar. For instance, you might only want to see 'Work' events but not 'Home' events during the day.

However, beware that if for example you add an event to your 'Work' sub-calendar on the Mac, but that same sub-calendar is un-ticked on the iPhone, the event will not appear until you choose to show that sub-calendar. This will manifest like a sync error, when in fact the data has synced, you have just inadvertently chosen not to show it in the calendar app.

4 – Your sharing is set up incorrectly

Sometimes the problem is that a 3rd party, such as a colleague or family member, is trying to share their calendar with you but you cannot see their events or changes.

If you're using Apple iCloud, you can share any of your calendars with other iCloud users. The same is true with Microsoft Exchange and Google Calendar.

Generally speaking, there isn't much you can do to troubleshoot this apart from un-sharing the calendar and then re-inviting the third party again. The process is slightly different for each service provider, so search their support pages directly to confirm the process.

Most of the time, un-sharing and re-sharing will work and reset the synchronisation. The only reason this might not work is when there's a further, underlying password or syncing problem with the account, covered by the various points above.

5 – General troubleshooting

Most calendar syncing services have a web-based calendar, which is really useful for troubleshooting:

Firstly, by logging into the above services using your web browser, you are confirming that you know your calendar service account password is correct. That's a strong start.

Secondly, a useful check is to create a new, test event in the web-based calendar. That means you are 100% certain your calendar event is stored on the service provider's system, completely independent of any problems your devices might be having. If any of your devices fail to download the test event to their calendar, you know there must be an issue with that specific device, rather than any of the others.

Lastly, you can try this in reverse. Create a test event on each of your devices, then check to see if any of them fail to appear in the web-based calendar. This diagnoses a problem with your device being unable to send changes to the calendar service provider.

It's really just a process of elimination to work out which device(s) are not working and why.

So there you have 5 common issues and tips for troubleshooting a calendar synchronisation problem between your devices. We hope this makes sure your diary is always up-to-date on your Mac, iPhone, iPad, Android device or Windows PC.

If you are still having problems with you Apple Mac, iPad or iPhone calendar not syncing then please get in touch with us.