Amazon Prime Day is changing. This year's sales event is 4 days long, running July 8th through the 11th, and there are new special sales dropping at midnight. So, Amazon's out here messing up sleep schedules to sell discounted TVs and vacuums.It's different than the Prime days of the past. So, here's what you need to know to navigate the chaos and make sure a deal you're getting is really a good deal. This is the 10th year of Amazon's July Prime Day sale.It's designed like a Black Friday shopping event, but ...