iOS 5.0.1 (iPhone 4s) unable to synchronize with Internet Calendar File (ics) I make use of an ics file that is hosted on my own iron on the Internet for various reasons, most importantly that I make use of Tasks, which Google Calendar is unable to synchronize with any WebCal client.

As for WebCal clients, I make use of Mozilla Sunbird on my main Windows workstation, Mozilla Lightning in my eMail clients, and iCal on my Mac laptop. I am able to use that single ics file to keep them all updated with not only events but also tasks (which, as I said, Google Calendar cannot do).

I host on my own iron. I run and operate my own servers under my own static IP address. I have a number of domain names pointing toward it, so it hosts web sites. I have created a single WebDav account in a directory on the “catch-all” http account (which is used to display a generic message if there is no website set up for that domain name). Any web browser or device is free to download the ics file, but the directory itself is password protected so that WebDav updates cannot be done by anyone except me.

All my WebCal clients can connect to the file, and can update it without fail, except the Calendar app on iOS/iPhone. iCal on Mac OS X 10.6 is also able to synchronize (read AND write to the file), so I know it isn’t an Apple-specific problem.

I am running a brand-new iPhone 4s, which is updated to the latest iOS 5.0.1. It is NOT jailbroken.

If I bring up the url in Safari using a standard http:// connection, it asks to import the entries -- but this is NOT what I want. I want to be able to synchronize with the ics file, and NOT just have a one-way import. I want to make entries in my Calendar app, and have the changes come up on my workstation under Mozilla Sunbird -- and that requires synchronization, not importation.

If I replace the http:// in Safari with webcal://, I get a “Cannot Subscribe. Could not subscribe to the calendar X from Y”.

If I go into Settings, go into “Mail, Contacts, Calendars” and add a new Subscribed Calendar, this also fails. Putting in the full url causes an error message, “Calendar Subscription: Unable to verify account information”. This is particularly confusing because my ics file is freely downloadable by ANY internet-connected client, be it web browser, WebCal client or anything else that can make use of an http connection. My iPhone is the first ever client that has been unable to access the file.

If I select OK I can put in some more information, but adding the username and password does nothing to improve the situation (SSL does not exist on my server, and is turned off by default anyhow in these settings).

So I am very badly confused. I would like to have my iOS Calendar synchronize itself with my Internet-hosted ics file so that I can make both events as well as tasks on my iPhone and have these items show up on any other device that I have a WebCal client set up on. How do I go around doing this?
Same issue for me.

A workaround is to copy paste the http:....\file.ics to your Safari, then the process works. But it's not user-friendly; I also want to tap on the link in my email, and then have it automatically update my calendar.