Test to confirm obi and day do not give macc?
What I mean is, you've done Wind Obi on Windsday with and Obi and Threnodies/Ninja tools and Fire Obi on Firesday, but have you confirmed that you'll never get a day bonus on Windsday without debuffing the monster or using an Obi?
I got Iceday bonuses on Spiders without an Obi, but about 30% of the time. Spiders are weak to Ice, allegedly, so it doesn't really tell us where Ice is in the order. I share Nynja's skepticism about everything being weak to Ice or Thunder on Wiki. Especially common Black Mage targets...