The Shopify app “Hurrify” is made by a company called Twozillas. It can be used to create various fake urgency messages, one of which is a fake countdown timer. In the first image, you can see what a user typically sees on a site that uses the Hurrify countdown timer. It's very prominent, animated and claims that the sale will end once the timer hits zero. However, the admin interface for sellers (second image) has a default configuration to "Run the campaign allover again" which means that the counter simply resets when it reaches zero.
Update April 2023: Hurrify appears to have been banned from the Shopify app store.