I've been using EDD (and EDSM) for just over a month now. I've logged 658 sytems (651 new, I'm out exploring).
I've not played for a couple of days (got sucked into playing Fallout Shelter!) but I decided to fly a bit today.
On starting EDD I noticed that is it up to 998862 systems logged, not far off a million.
Two thoughts - who will log the millionth system and will it be recognised somewhere as a special event?