Time period this takes place?

Wikipedia describes it as "Depression-era Yorkshire, England", which is about the time I thought it takes place.

The book was published in 1940, with no suggestion that it was anything other than contemporaneous with the story.

You're right, it is hard to tell exactly what time it is. I remember "James Herriot" writing in his ALL THINGS... books of areas so remote in Yorkshire, the industrial age had not yet reached it, even in the 1930s. With no radio or phonograph to entertainment, the people he described just sat in their front parlors and stared off into space in the evenings, until it was bedtime.

1930s, just before World War II, but apparently some people in Yorkshire dressed in the style of 30 years earlier.