Forum:KB:Galactic Standard Calendar vs other planet solar cycles?

I'm trying to figure out how the Galactic Standard Calendar can line up with planets that have different solar cycles. It mentions the use of Hyperdrive Theory (unsourced) in the article on GSC, but the explanation doesn't quite click for me. As far as I can tell, hyperdrive is something that is used to travel many light years (which is a measurement, not a period of time)? Are there any other explanations of how the Galactic Calendar works with planets that have different solar cycles?