WooCommerce Simple Storewide Sale is a plugin and excellent marketing tool that allows you to have sitewide sales for special occasions such as Black Friday, Christmas, clearance, store anniversary, or any other special day. You can specify a percentage or fixed value discount, the start and end date of the sale, exclude certain products, product categories, product types, and tags, add a sitewide notification about the sale, or have a notification before the sale begins.