To show a countdown timer, add the app block to the product page and enable it in the selling period rule.
Prerequisite: Use an Online Store 2.0 theme. The countdown timer is displayed with an app block.
Add "Countdown Timer" to the product template.
(1) Open the theme editor
From Shopify admin, go to Online Store → Themes, then select "Customize" for the target theme.
(2) Open the product template
In the theme editor, open the product template.
(3) Add Countdown Timer
Select "Add section" or "Add block," open "Apps," then add "Countdown Timer." Move it to the position you want.
(4) Turn on the theme editor demo if needed
Select the block you added. If you enable "Show demo in the theme editor," you can preview the timer in the theme editor regardless of the selling period.
(5) Save
Change the design and text if needed, then select "Save" in the upper-right corner.
Adding the app block is not enough. Enable it in the rule as well.
(1) Open the selling period rule
Open the selling period rule you want to display.
(2) Enable the display
In "Before the selling period" or "During the selling period," enable "Show countdown timer."
(3) Enter the title and description
Enter the countdown timer title and description.
(4) Save
Select "Save."
Check: Open a product page with the rule in the online store, and confirm that the remaining time appears.