> so what you’re saying is there are indeed subtle differences and Northern California would have a tiny bit different time, but we just don’t acknowledge it?

Not really. The subtle difference between nearby places is in when the sun (and other things in the sky) rises and sets. There is no objective "time" at which these events occur. It's determined by the local horizon.

Muslims need to keep track of the sunset for fasting reasons. They are advised that if they happen to be at the top of the Burj Khalifa, they should remember that the sun sets three minutes later at the top of the tower than at the bottom. That doesn't mean it's "actually three minutes earlier" at the top of the tower. It's the same time as it is on the ground, it's just high up so the sun is above the horizon longer.