Here's what I do for times when I have multiple cameras working. Before you shoot, hook one of the cameras up to the same computer with EOS utility running. Go into the camera menu on the utility until you find the date/time section. Make sure the camera is in sync with the time on the computer. Hook up the next camera and do the same thing. Now they should be all on the same time. Once that is done, when you want to sort them on any of the software or picture viewers that you have, you just need to select date taken and then pick if you want them from last to first, or first to last.


Now if you were asking how to do it if you had not done a sync, refer to what everyone else is saying. Sorry if mine didn't help at all, but that's what I do to prepare.