Q: Contacts app

Hello kawaii_kbear07,

Thanks for using Apple Support Communities. 

I see that your iPhone's Contacts app is changing a contact's birthday to the incorrect year. I use my Contacts app to track birthdays as well, so I know how important it is we get this issue resolved. I have several things for you to try.

First, if your Contacts app is not responding and accepting your changes, let's go ahead and Force Quit the Contacts app using the steps below:

Force an app to close on your iPhone, iPad, or iPod touch

Next, use the steps below to give your iPhone a fresh restart:

Restart your iPhone, iPad, or iPod touch​

And finally, after you've completed a restart, please open the Contacts app and see if you get the same incorrect year result. 

Additional help and resources can be found in the iPhone Help guide below:

Contacts at a glance 

Cheers!