My parents have a shared birthday.

来源：Shared birthday指的是两个人的生日在同一天。

英文例句：

My parents have a shared birthday, so we always celebrate together.
It's so rare for my parents to have a shared birthday, but it makes it easier for us to plan their birthday party.

中文翻译：

我的父母有同一个生日，所以我们总是一起庆祝。
我父母有同一个生日是很少见的，但它使我们更容易策划他们的生日派对。