Everyone knows that both Christmas Day and New year's Day always fall on the same day of the week. However, in 1939 the year of the outbreak of World War II, Christmas fell on a Monday and New Year's fell on a Sunday. Why?
Christmas and New Year's Day occur exactly one week apart. So a New Year's that occurs right after Christmas should be on the same day of the week. But in the year 2020 Christmas will occur on a Friday and New Year's on a Wednesday.
Why is this?
What day comes two days after the day immediately before the day three days after the day immediately before the day which comes two days after Sunday?
