Add birthdays to Contacts on Mac
You can add a birthday to a contact’s card, including birthdays based on a lunar calendar (such as the Chinese, Hebrew, or Islamic lunar calendars).
In the Contacts app on your Mac, select a contact.
Click the Add button , then choose Birthday, or choose More Fields, then Lunar Birthday.
If an option is dimmed, it’s already on the card.
Enter the date, then click Done.
Siri: After you add a birthday to someone’s contact card, you can say something like: “When is Jane’s birthday?” Learn how to ask Siri.