Fully parse dates with year, week, and day of month #3
Description
This isn't a priority since I'm not aware of any kind of format that actually does this, but it should be possible to write and parse date formats like %Y-%W-%d. Currently the parsed output date would be Sunday on the week number of the given year. Instead, when day of month is given but day of week is not, the parser should still be able to determine the date exactly.