I do have some of that thanks to the IRAs; they reduced the amount I owed on, at least. (In fact, last year, they reduced the amount I owed enough that I wouldn't be at risk of penalty, which turned out to be a powerful motivator to getting me to actually put the things through.)

I suppose I really should have worked out how much I could have put as a last-year's-contribution to reduce the tax bill, and see how much I'd have to send to come out with a refund too. But that's a little too much work, and it's moot in two hours and fifteen minutes anyway.