I don't read a lot of fantasy, but I find what makes worlds believable for me is a sense of times past. So, in times past, they didn't measure age by years, they measured by summers. One month wasn't the varied accumulation of days it is now, it was one moon. A minute wasn't how long it took for the big hand to go around once, it was how long it took for the bucket to fill with water. I think one takes one's measurements from one's surroundings, one's own experiences, one's world. Using simple words to describe larger concepts. I read your blog, and it sounds like the issue is a little bit larger for you than the post here in the forums suggests. For me, a pretty good overview of how the measurement of time developed is When Time Began by Zecharia Stichin. It gave me a good sense of the different ways that time can be measured.