Sync via iTunes
This is the oldest, tried and true method of syncing. Syncing is done via a wired connection between your iPhone and your Mac. Calendars in iCal are synced with the Calendar app on your iPhone.
To use this option, connect your iPhone to your Mac, using the Dock connector cable, and launch iTunes. Find the iPhone listed in the Devices section. Select it and go to the Calendar section of the iPhone’s Info tab. From here, you can select to sync either “All calendars” or “Selected calendars.” With the latter option, you have the flexibility choose exactly which iCal calendars you want to sync (assuming you maintain more than calendar).
Syncing is bidirectional. Almost any changes you make at one source transfer to the other.
With the latest versions of iTunes you can sync subscribed calendars listed in iCal to your iPhone. This does not require iPhone OS 3.0.
Brief background on subscribed calendars: Subscribed calendars are calendars that you connect to via the Internet; they are published and updated by someone else. Your access to such calendars is typically read-only. For example, you might subscribe to a Movies calendar that shows which movies are opening each week. To work with the iPhone, subscribed calendars must either use the CalDAV or iCalendar formats.
To subscribe to a calendar in iCal, you need to know the calendar’s URL. These URLs typically either begin with “webcal://” and/or have “.ics” in their name. The most common way to find such URLs is by going to a Web page that lists calendars (as one example, Apple maintains a list here). On your Mac, if you click such a calendar URL from Safari, you should be redirected to iCal where the calendar is added. Otherwise, you can paste or type the URL directly into iCal’s Calendar > Subscribe text box.
You can publish your own calendars, to which other people can then subscribe. In iCal, this is done via the Calendar > Publish command. Your calendar is published either to your MobileMe iDisk or to a WebDAV server. To have people subscribe, you would typically send them an email, containing the calendar’s URL.
Okay, enough diversion. Back to the main topic at hand.
When you’re done syncing, open the Calendar app on your iPhone. Next, tap the Calendars button in the upper left corner of the screen (if the button isn’t there, you don’t have more than one calendar synced). This takes you to a list all of your synced calendars. Your iTunes-synced calendars will be in a section called “From My Mac.” From here, you can also select whether to display only a selected calendar or “All Calendars.”
Sync via MobileMe
If you are a MobileMe member, you have a great alternative to iTunes syncing: you can sync your calendars via MobileMe. The primary advantage of this method is that, assuming your iPhone is connected to the Internet, events update nearly instantly. For example, if you add an event to iCal on your Mac, the event data transfers to MobileMe in the cloud and from there syncs to the Calendar app on your iPhone — typically all within less than a minute. And vice versa. There’s no need to wait until you can connect your iPhone to your Mac to sync in iTunes.
Brief background on setting up MobileMe-iPhone syncing. For iCal/MobileMe syncing to work with your iPhone, you first have to set this up. Assuming you’ve already set iCal on your Mac to sync with MobileMe, your next step is to go to Settings > Mail, Contacts, Calendars on your iPhone. From here, set Fetch New Data to Push. Also, from the me.com settings on your iPhone, make sure that the Calendars option is ON. The names of all your MobileMe-synced calendars should now appear in the “me.com (MobileMe)” section of the Calendars list (the same screen where you previously viewed the “From My Mac” list).
The biggest downside of MobileMe syncing, as compared to using iTunes, is that you cannot sync subscribed calendars. Also unlike iTunes syncing, you cannot select which specific calendars to sync. All calendars in MobileMe get synced to your iPhone.
New in iPhone OS 3.0, you can choose to sync via both iTunes and MobileMe. In iPhone OS 2.x, you had to choose between one method or the other. I see little point in using this dual syncing to sync the same calendar via both methods; this is likely only to lead to confusion. However, dual syncing allows you, for example, to sync subscribed calendars via iTunes and the rest of your calendars via MobileMe. This offers push updating for your own calendars while still getting subscribed calendars to show up on your iPhone.
“Sync” via iPhone only
Syncing (actually, subscribing) directly via the iPhone is a new option in iPhone OS 3.0. Essentially, it allows you to subscribe to a calendar from your iPhone, bypassing iCal and MobileMe altogether. Such calendars are listed on your iPhone but do not sync back to MobileMe or iCal.
Why might you wish to add a subscribed calendar to the iPhone directly, rather than syncing it via iTunes? The main reason is that calendars subscribed directly from the iPhone are updated whenever the calendar is changed, as long as you have an Internet connection. You don’t have to wait to sync your iPhone in iTunes to get updates. Again, while you could list the same subscribed calendar via both methods, I see no reason to do so. Choose one way or the other.
How do you add a subscribed calendar to your iPhone via this method? You have two choices:
Click on a link for the calendar URL. This avoids having to do any keyboard typing on your iPhone. If you know the URL, mail it to yourself from your Mac. Now go to Mail on your iPhone to receive the message. Tap on the link and you will be prompted to add the subscribed calendar. Alternatively, via Safari on the iPhone, go to a page where the calendar link is listed and tap it. Again, a message will pop up asking whether or not you wish to subscribe. Tap the Subscribe button.
Directly enter a URL. Go to Settings > Mail, Contacts, Calendars > Add Account… > Other > Add Subscribed Calendar. From here, type or paste the URL.
Note: From this same “Other” screen, you can add a CalDAV account (such as a Google Calendar) or an LDAP account (for contacts). These are subjects for another article!
Whichever of the two methods you choose, such calendars are now listed in the Subscribed section at the bottom of the now familiar Calendars screen.
The account settings for these calendars are found at Settings > Mail, Contacts, Calendars. If you tap the calendar’s More Info button here, you’ll be taken to a screen where you can edit settings, including to Delete Account (if you wish to remove the calendar at some later time).