Boost sales with a countdown that show the remaining time for an offer or the quantity available for a specific product. With a countdown displaying on your product page you create something like a scarcity mentality in people, urge them to buy right now.
However, if you are launching a promotion campaign, you would like to allocate a specific value for a specific product. So you can do that by using Metafields Guru App.
You can refer to this link to understand how to use Metafields
60 days, 3:59:12 or
Video: you also can follow this tutorial video here: