WordPress Countdown plugin is an nice tool to create and insert countdown timers into your posts/pages and widgets.
YITH WooCommerce Product Countdown allows you to put a digital counter in the product pages
The official #1 most intelligent, scarcity countdown timer plugin ever created for WordPress to expire posts AND pages on autopilot!
WordPress plugin to add a countdown timer to your website. Display a timer and countdown to any day, time, or event.