Read Thread: Planning a plant
I currently have boxes on my reserved list dating back to 2015. I have been on a planting binge for the past two weeks and have cleaned a lot of them out and all I do is change the date to the actual plant date before I activate the clues.
I'd recommend doing that after you activate the clues. Off the top of my head, I think AQ might automatically set the plant date to the activation date because I know a lot of people don't edit that sort of thing when they make a box live and if you make it live, there's a good chance that is the plant date. (Or, at very least, very close to it.)
I could be wrong.... this is off the top of my head and I'd have to look at the code to be 100% certain. But there's definitely no harm in changing the plant date after it's activated and you have to edit the listing anyhow to mark attributes, add a location and anything else that's specific to the box type you activated. (The reserved listing only let's you add options that are the same for all box types.)