A countdown timer should appear on each of the following:

• Every product - State the date and time a specific product's sale will expire

• Promotional emails - This will help in building anticipation days or weeks before your Black Friday and Cyber Monday sales.
• Landing page - A website banner timer to reveal when the actual sale will commence so people can plan ahead when to start online shopping.
• Social media posts - A countdown timer section can be added on your social media page to hype the event and to make sure that your customers know when to save the date. (Here's a tool to look at)