Almanacs assign each day a 'moon sign' for farming: water signs for planting, fire signs for weeding and killing things.

The system maps zodiac elements onto garden jobs: Cancer, Scorpio and Pisces for sowing; Aries, Leo and Sagittarius for cutting back. It's a complete, internally consistent scheme with no measured effect, and it's still printed every year because it turns a vague chore list into a schedule.