I face the same problems all the time.
Here's a far more interesting take on tibetan astrology, for one: http://www.magastral.com/astrotibet/cal ... ctuel.html
it's in french and english in pieces so you may need to look a couple things up. But it gives you a lot of really cool info like the animal du jour (today is an iron Dragon day! How cool!)
Anyway, I think on the one hand, it's all made up right? It's all mind.
On the other hand, this is magic with some serious tradition behind it. I like to do it just as an act of mindfulness and an aspiration practice. Get your hair cut on the 10th day of the lunar month for great power to help beings. Get it cut on the 8th and you will meet lovely young companions wink wink.
However, if it's a bad haircutting day, I just say vajrasattva as much as usual and then include the aspiration: if any negative forces result from this, may it be Tonglen that takes away the negativity of other beings getting their hair cut on this day. Or even just all beings in general. That way, it is a source of merit and the more negativity that results from it, the more you profit, right?? Basically Bodhicitta makes every situation win/win.