A week is seven days, and the ninth week is nine or seven days. 7x9 263 (days). July is a big month of 3 1 day, and August is also a big month of 3 1 day. Two months and 62 days. In the second half of July, August has 62 days. September in the second half of the year begins on the 63rd day. So the ninth week of 202 1 is 1 1 in the second half of the year. (the first day)