Did the Romans observe time the observance of religious holidays involving planetary positions? (such as Saturnalia)?

was it based on the position of the Sun in relationship with the earth? or maybe its location in relationship with a star ? can explain also about the other major gods/deities, such as Hades., Pluto...Neptune, Apollo etc? what about "All Saints Day" and "Halloween? Why Saturnalia is the one that most often hear about in history accounts?

Obi Wan Knievel

The Romans didn't give a damn about planetary positions. They, unlike yourself, had much more important stuff to think about.