Don't most laws work like this: "As of Date X, Y will be illegal." So refiners basically stop making high Sulphur diesel, but date X is far enough in the futu

Don't most laws work like this: "As of Date X, Y will be illegal." So refiners basically stop making high Sulphur diesel, but date X is far enough in the future that there's time to use it all up before the law takes effect.