Birthday registered on Contacts app, shows up in Calendar app, but does not show me an event reminder?

So I have entered a birth-date for a contact in my iPhone's Contacts app. When I do this, it shows up in my phone's Calendar app. However, I do not receive an event reminder for when the birthday is up and coming. Is there a way for me to get notified of this event by the Calendar app through an event reminder, like it reminds me of any other event made in the Calendar app? I don't want to consider getting a third party app because I just don't find it logical to have multiple calendar apps because it takes up too much space, and I'll probably end up using the third party app more than I do with Apple's default Calendar app, which defeats the purpose of them installing it by default in the first place.

Hope anyone would be able to help me with this. Thank you!