YITH WooCommerce Product Countdown allows you to show a specific countdown for each of your products on your product and/or category pages.
The combined use with YITH Pre-Order for WooCommerce allows you to show a countdown on a pre-order product until it will be available.
After installing and activating both plugins, the availability/release date configured in the pre-order product will show in the countdown dates.
If you want to customize the text shown next to the countdown, go to YITH > Pre-Order > Style and enter the text in the option Label for YITH WooCommerce Product Countdown.
This is how the countdown for your pre-order product will show on the product page.