Yes, you're on the right track. I've updated the pin hint, so it should be easier to figure out now.
Yay, thank you! I'd actually tried a lot of codes like that, but I think the extra complication of American / European date formats meant I'd missed that exact one. Still, now that I can play the game it's really fun!
Very short, obviously, but lots of potential. It reminds me of Strange Horticulture, if you know it.