If, say, horseback travel is an anachronism today, what do you call flying machines in the medieval times? Rocketry in ancient China? Celestial navigation in Polynesia?
They’re all anachronisms. It means something in the wrong time - future or past doesn’t matter.
I’d think ‘congruity’ would be the opposite of ‘anachronism’. But that’s not what you meant.
Good answer! 
From the OED definition of anachronism, which you’ll note also supplies the word you’re looking for - parachronism.
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I wouldn’t call horseback travel an anachronism today. Lots of people still do it in the back country. My understanding of anachronism is having something occur or exist in a particular time that simply didn’t truly ever actually occur or exist at that time. Rockets in the sense of what we would call fireworks certainly would not be an anachronism in ancient China.
I recommend you look at the Wikipedia article on anachronism.