Bed Bath & Beyond's 20% off coupons

We have 2 registries, one at myregistry.com and a linked one at BB&B. There are some items (such as Le Creuset cookware) available at BB&B that I put on the myregistry list instead, because I wanted guests to have the option of shopping around for the best deal instead of having to purchase through a specific retailer such as BB&B. However, just today I purchased a wedding gift for someone else off their BB&B registry and noticed there's an online coupon to save 20% off a single item, basically the infamous BB&B 20% coupon in online form. This online coupon expires in February and our wedding is not until August, but I'm wondering if, like the paper coupons, it's something they run regularly that I can count on being available in the summer as well. Any thoughts? I want to save my guests as much money as possible.