Lightening Deal affected by lowering price for one day?

So a lightning deal is pegged to the lowest price in the last 30 days but does anyone have any experience with testing this? Can you lower the price for just one day, an hour, 2 days?

I know I can do a coupon without affecting the lightning deal but I want to lower the price because my understanding is people who have it in their carts will be notified only if the actual price is lowered not with a coupon.