Overview
T(-) Countdown is a customisable countdown timer that can display years (optional), months (optional), weeks (optional), days, hours and seconds. Countdowns can be placed on a post or page using either a traditional shortcode, or a Gutenberg Block. This plugin is the next generation of jQuery T(-) Countdown Widget.

T(-) Countdown Control is an advanced plugin that adds scheduling for multiple recurring countdowns for repeating events
Add-on plugin for T(-) Countdown and T(-) Countdown Control that allows events, such as changing content or firing a javascript function, to be triggered at specific times during the countdown