The absolutists insist that spiritual beings everywhere must share a zodiac, which requires astrologers to have a really good galactic map on hand. Galactic arms, globular clusters, stellar nurseries, and of course the galactic core have their assigned attributes, and the alignment of your birth-world with local bodies and those Galactic signposts serves as a predictor for your behavior, the behavior of those around you, and insert another 22.950 credits for a complete reading.
Chiropracticioners of the 31st, by comparison, ignore the relevance of the stars completely, insisting instead that the relative position and alignment of mysterious objects known as "vertebrae" (which are supposedly inside your body) dictate very specific things about a person, such as whether he/she will be experiencing unusual neck pain, should choose to lift from the legs rather than the back, or will be spending another 45.599 credits with a chiropracticioner next week.
Commentary: In a curious coincidence, on November 17th, 2004 (the date this strip was written), Howard shared the dialog with his chiropractor. He probably would NOT have done so had he read his own horoscope for that day, which read "It's all too easy easy today to open your mouth and put your foot in it...There could also be a discrepancy about what you think is funny and what someone else finds amusing, leading to some embarrassing moments."
No, I'm not making this up.