Well this particular one... I was looking at the envelope from the bank, it had a small globe on it and then it hit me I could make a riddle with coordinates, but I've given up that idea since I wanted to make something more simple and thought of time zones, plus and minus and counting from the front and back and I used Wikipedia list of time zones.
And the ghost story - well Itachi and I had some misunderstandings regarding ghosts in the ghost thread in the others forum and decided to use that as a story!