The Solar Calendar is the particular situation we've been talking about here for the last week. It's one near and dear to my heart. We've been working on it hard for a long time. But it's not the only situation for Mobile Frame Zero.
Like, this guy:
I don't want that guy, with his chugging steam engine and Prussian cap to be out beside my Hi-Legs. It just doesn't make sense.
But man, I want to play an army of cavalry against him! I want to field a dirigible! I want gattling guns that go "pokpokpokpokpok!" instead of "brrrrrrt!" I want a pot-bellied, four-legged Behemoth with a howdah on its back at the head of an army of Indian revolutionaries and their clockwork infantry!
Other times, we might want everything to be taking place with jet aircraft, or maybe fields of Fremen and Sardaukar.
When we all sit down and make these details up, we're making a new calendar. We might call it the Cold War calendar year 1983, or The Padishah Emperor's Year 10191. Give it a time and a place to start, and consider everything else we've made up to be inspiration at most.
And you might want to do things that more subtly violate aesthetic principles of the Solar Calendar, too. Maybe you want 40-meter robots wielding giant hammers, or ancient ones made of robot lions. Don't feel constrained by the Solar Calendar, but don't shoehorn stuff in that doesn't fit, either. Make a new one and tell everyone about it with pictures and descriptions!