Go to a calendar (or create a new one) and tap the "i" to its right. You will then have the option of sharing it with someone.
(Depending on your provider's security settings, this might be hidden, but it works with iCloud.)
Go to a calendar (or create a new one) and tap the "i" to its right. You will then have the option of sharing it with someone.
(Depending on your provider's security settings, this might be hidden, but it works with iCloud.)
Add birthdays to your contacts and their birthdays will appear in your calendar.
How to use Siri with Calendar, drag-and-drop events, Focus filters, and share calendars on iPhone