The "Date" column takes the earlier of "Date created" and "Date modified", ignoring "Date accessed", unless there is a "special" date field such as an Exif-header in a JPG, which takes precedence no matter whether it is before or after other dates present... just as @Richard guessed:
The reasoning seems to be that when you copy a file, the "Date created" of the file copy is the current date, while the "Date modified" is carried over from the original file. So in this case the "Date Modified" contains more information about when the content was created/changed, so might be more relevant to some users than the date the file was copied.
