Nowadays there are two starting clocks:
The world setting one and scenario one.
The world setting one should not cause accelerated time. It should be as if the cataclysm (the lore event) started just before the current season.
The scenario one should cause accelerated time. It should be as if your character camped out the first few seasons.
I’m not sure if they work correctly together. Trying summer start world + summer start scenario might cause an autumn start or something like that. Didn’t test it, but the code doesn’t look right.