I thought it went back to 2005 when in the aftermath of Hurricane Katrina, the Saints had to move their opening game against the Giants to the Meadowlands but the Jets had a home game that Sunday. It forced them to move the Saints-Giants game to Monday night when there was a game already booked so they started the Saints game at 7:00 and kept the regular game at 9:00pm, They had two games going on simultaneously for an hour and depending on what market you were in, whih game you saw.
I remember because I watched the Saints game on a 3 inch battery-powered black and white TV in Gulfport, MS and eith no power may have been one of the few watching it,