Aviation geeks: fasten your seat belts.
This video from Flightradar24 shows the 164,209 flights the website tracked on April 1, 2016, compressed into one minute.
The time lapse covers the first day of April from 0000 UTC (8 p.m. ET) to 2359 UTC (7:59 p.m. ET).
UTC is the universally accepted standard measure of time used in aviation. It is interchangeable with Greenwich Mean Time or GMT.
According to Flightradar24, air traffic peaks between 1000 UTC (6 a.m. ET) and 1400 UTC (10 a.m. ET).
By 0700 UTC (3 a.m. ET), skies above the U.S. begin to clear, leaving just the red-eye flights on the radar.
According to the U.S. Department of Transportation, U.S. and foreign passenger airlines operated 26,000 flights per day to and from the U.S. and within the U.S. in 2015. That equals 2.5 million passengers each day.