I personally hate those kind of sales pages because a timer like that is just a cheap marketing trick to get people to buy the product. What I would rather do is launch a product and award people who buy the product within a day or 7. I would put a timer on the sales page with a text like this:
"This product has been launched at [date] and to award people who decide to buy fast, I give you 10% discount if you buy this product before [date]. Note: This isn't a cheap marketing trick, this special offer really ends at [date]."