This article explains how to sync a Yahoo Calendar with an iPhone calendar. Instructions apply to iPhones running iOS 12, iOS 11, or iOS 10.
How to Sync Yahoo! Calendar with iPhone and iPad Calendar
Yahoo Calendar is available on the iPhone as part of a linked Yahoo Mail account. With Yahoo Calendar activated, events will automatically appear on your iPhone calendar.
It’s easy to sync Yahoo Calendar and iPhone Calendar in the background. Changes to Calendar will be updated on both iPhone and your Yahoo account.
If you haven't added Yahoo as an email account to iPhone Mail yet:
