I'm pretty confused about what you would want to end up with.  If you have 6 different dates, and you want to have a map of the types of changes, do you want the whole history of change to be considered in the definition of each output map unit?  In that case, you would probably have a whole lot of output map units.  For example, you might have one unit that is veg-veg-veg-veg-not veg-not veg, and that would be different than a unit that had a history like veg-veg-veg-veg-veg-not veg. And if you have more than one not veg classes that you want to distinguish, it would be even more complicated.  Basically, you would have 6 factorial potential output classes, right?  That is 720 output classes.  Is that what you want? ENVI doesn't have a tool for that, but it does have a tool to show you the changes between two times.  So, you could use your first date, and last date.  You can find that tool under Basic Tools > Change Detection > Change Detection Statistics.  With that tool, you specify a classified image showing the initial state and a classified image showing the final state.  ENVI returns a series of maps that show the types of changes, as well as a table showing the statistics for each input and output class, in terms of what it changed from and to. Peg