Random thought: Connection between 5:5 and D5?
I was looking at my calendar today, and realized that 5/5 happens to fall on a Sunday this year. A long time ago, I started abbreviating Sunday with the single letter "D" so as to not confuse it with Saturday. So this year, 5/5 also happens to be "D 5".
5:5 = D5?
It's probably nothing, but I wanted to submit it for anons' consideration.