Yesterday (a UTC day) in two minutes, shown in your local time. Drag to turn the globe, pinch or scroll to zoom; left alone it turns again.
Flight data: adsb.lol contributors, under the Open Database License, as are this view's replay files. Dense over North America and Europe, thin elsewhere. Nobody hears flights over the open ocean: the fainter ones there are estimated, a straight great-circle line from where each was last heard to where it was heard again.