how to add billing birthday date field in checkout page woocommerce

Hi @onuproy01,

To add the DOB field, you have two options: you can either use a plugin or write some custom code. If you want to use a plugin, I’d recommend the WooCommerce Checkout Field Editor. This plugin allows you to add custom fields to your WooCommerce checkout page, including a date picker field that could be used for a birthday.

In addition, if you want to use a custom snippet code, you may follow this guide: https://njengah.com/woocommerce-date-field-checkout/

I hope this helps! If you have any other questions, feel free to ask.