That’s days played, so certainly longer than 3 calendar days.
This would be Virillustris, my Frost Mage.
He is mostly a product of dungeon finder. Fully outfitted in heirlooms he held his own on the damage charts. I quested until I got flying in Outlands, then dungeons. I knocked around Northrend with a few of the intro quests, but otherwise bypassed all content past the initial landfall. I never even ventured into Mount Hyjal or Vashj’ir, or anywhere beyond. Panderia, I fought my way off the attack ship and into the inn there. I set it as my home, because I’m a mage and it doesn’t really matter, and that was it for questing outside of dungeons in Panderia.
Now I command a Garrison in Draenor. And I have to quest to acquire the followers.
Dungeon Finder is a really great tool. See content while you play your class, and otherwise, while waiting for the next dungeon to pop, be able to just chill, relaxing with music and reading the internet.
I’ve got some fairly high days played on my other characters. The raiders.
But 3 days played to level 90? It went by in a blink, comparatively.
I’d hope I can do the same for my Warlock. The fact that their class hall is on another freaking planet come Legion is kind of cray cray.