Not Caldav. Old.
read this: Works ...(from prior post)
Below is the response I got from Yahoo! Calendar Support.
Yahoo! Calendar Support essentially says iOS users should no longer use CalDAV account method but instead use the built in Yahoo! account option (Settings > Mail, Contacts, Calendars > Add Account > Yahoo!). Of course, this used to work for the calendar before iOS 5. Since then, all of us are trying the CalDAV option as an alternative.
Also, I noticed yesterday that Yahoo! updated the Yahoo! Calendar on the web. It has a nice look and feel in an attempt to better compete with the more robust Google Calendar. Perhaps, Yahoo! has been working hard at this and the integration with mobile devices has been on the back burner.
Suggestion to Yahoo! users on iOS 5 devices - Try using the aforementioned standard method for getting your calendar on your device. With the release of the new Yahoo! Calendar, maybe it's working now. Me? I gave up a few days ago. I'm now using Google Calendar.
Without further ado, here's the message from Yahoo! Calendar Support.
Thank you for writing to Yahoo! Calendar.
I understand you are experiencing sync issue with your Yahoo! Calendar using your iPhone device. I apologize for the inconvenience this has caused you. Let me address your concern.
If you recently upgraded the operating system on your iDevice (iPhone, iPad, iPod Touch) such as with the recent release of iOS 5 software for Apple iDevices that could be the cause of the syncing issues.
You can delete the Yahoo! account from your Apple iDevice and recreate it, forcing a new sync, which should bring all your information over from Yahoo! Calendar.
Please note that CalDAV accounts are no longer needed on your iDevice to sync with Yahoo! Calendar and you may delete the CalDAV account if you have it set up on your iDevice. If you have a CalDAV account set up and do not delete it from your iDevice, you risk getting duplicate calendar layers & events on your iDevice and in Yahoo! Calendar.
To remove your Yahoo! Calendar CalDAV account from your iDevice:
- Go to your iPhone, iPad, or iPod Touch "Settings" application.
- Tap "Mail, Contacts, Calendars."
- Tap "Yahoo! - Calendars, Reminders."
- Tap "Delete Account", Confirm deletion by tapping "Delete Account" once again.
How to sync your Yahoo! Calendar and Yahoo! Address Book with your iDevice (iPhone, iPod Touch, iPad)
- Go to your iDevice's "Settings" application.
- Tap "Mail, Contacts, Calendars"
- Tap "Add Account" and then tap "Yahoo!". You may already have a "Yahoo!" Mail, Contacts, Reminders, and Notes account set up; if so just tap it under the accounts section.
- Enter your Name, Yahoo! E-Mail address & Password. You do not need to change anything in the "Description" field unless you wish to. Tap the "Next" button, upper right hand corner, when you have entered the information and Yahoo! will verify your account information.
- Click the "Save" button in the upper right hand corner
- Still in the settings for "Mail, Contacts, Calendars", set the "Fetch New Data" to every 15 minutes or whatever time increment you desire, you may leave the "Push" setting on or turn it off, it is not relevant to Yahoo!'s services.
- To ensure proper syncing between your iDevice's Calendar and Yahoo! Calendar, please make sure the "Default Account" account is set to one of your Yahoo! Calendar Layers from Yahoo! Calendar in "Calendars" found towards the bottom of the settings for "Mail, Contacts, and Calendars". It defaults to iCloud and if not changed to one of your calendar layers from Yahoo! Calendar, syncing will not work.
- You can come back to Yahoo! Mail, Contacts, Reminders, Notes to disable syncing for all or specific Yahoo! Services or to delete your Yahoo! Account from your Apple iDevice.
I hope the information provided has been helpful. Please don't hesitate to reply if we can be of further assistance.
Thank you again for contacting Yahoo! Calendar.
Yahoo! Calendar Customer Care
I posted a better solution several months ago. Every few months I get the "Caldav password incorrect..." All I do is go to settings, Safari and delete cookies and clear history. Then reboot the device. After that everything syncs both ways, including items added during the "password incorrect" state. This has worked at least 4 times for me. One of the times I had to re-enter the password as well, after the re-boot.
I got so frustrated with all of this that I just bagged the yahoo calendar and switched to google calendar. It syncs fine (<1 min from the time an event is added on the phone to show up on the computer and vice-versa).
If some of your residual yahoo events remain on the iphone/ipad, it's super easy to flip them onto your google account. Just open the event and change on your iphone and change the calendar it's associated with to the google calendar.
By the way, I'm largely having the same issue with my contacts (which I've been keeping on Yahoo). Changes are not synched consistently. I'm contemplating flopping those to either iCloud or Google. Shame on Yahoo...
Putting my two pennies worth in, here is how I sorted the issue.
one: exported my iphone calendar to iCalendar format using this method
three: my iphone calendar is now transferred to my yahoo account.
iphone 5, ios 6.1.4
Yahoo Calendar stopped syncing so I deleted my Yahoo Account and readded in. In the Mail, I made sure my Yahoo email account is set at default. I do not see Yahoo Calendar as option under calendar setting. When I goto Calendar app, it's completed empty, no entries what so ever. Yahoo Mail and Contacts seem to work fine, just Yahoo Calendar not showing at all? Anyone found what the problem is or solutions? Thanks.
there's another discussion thread on this....it looks like people with Yahoo calendar problem all of sudden not working is realted to having ATT or SBC email linked as the primary account. This is my situation as well when I first got the ATT small business email powered by Yahoo. But now Yahoo and ATT are separating their partnership. I have another Yahoo email account for personal use and the Calendar syncs fine with my iPhone since it's not linked to my SBC. That's the only thing I can think off. Curious to know how many of you also have either ATT or SBC linked that's causing this.
Here's the other discussion thread link:
I have been messing with this same issue all week! Over the weekend, my iPad updates stopped going to my PC Yahoo calendar. By Monday morning, the calendar had completely disappeared from the iPad!!! I've made numerous phone calls and tried all kinds of syncing to no avail. This morning, I finally tried opening a Google calendar and import my Yahoo calendar, but even that wouldn't work. :-(
One more thread that I started last month: https://discussions.apple.com/message/21969976
Also, I think I agree with macmeister and iphonemaven. It might just simply be time to change providers for good.