Remember that the order came down overnight and the various crews did what they could do, however, it's quite likely that most of the stripe-jobs were "tightened-up" a few days after the 6th, when the OPTEMPO slowed a bit (and the crew chiefs decided they couldn't stand to look at sloppy stripes anymore)...
One that was initially sloppily-applied could easily be properly masked and repainted starting around the 9th or 10th... In reality, it doesn't take but a couple/three hours to paint them on, depending upon the size of the aircraft... Obviously, a Spitfire or Mustang can be done quicker than a C-47, Sterling, B-26, etc...