So I searched through the old threads and I found some interesting information to get me started, but seeing as the threads were over four years old I am trying to reopen the topic.

I am currently in planning mode for an epic fantasy. It includes new species and places, but I am toying with the idea of leaving units of measure the same. As in, I would use inches and miles. My issue comes to the months of the years. I want to just leave the months with the names of this reality, ie March, August, October. Same for days of the week.

Would leaving such names the same be jarring to the reader when everything else of the world is different? I am curious what others feel about this.