Why does "file" change the creation time on some Unix systems?

[Guy Harris]

 >The "creation" time refers to the last modified time.  If the last time the
 >file was modified was at creation, well then it really is the creation time.
 >However, if the file was modified since creation, the two times will not be
 >the same.  The inode doesn't even save the creation time, so it is not
 >available.

Almost correct.  "ctime" isn't the last modified time, that's the
"mtime", which is the time the file was last modified (i.e., written to,
or truncated, or extended - i.e., any time the file size or the file
contents were changed).  "ctime" is the time the inode was last changed,
which includes modifications of the sort "mtime" reports *and*
modifications such as changing the owner of the file, or permissions of
the file, or number of links to the file.