Returns the time the file was last modified, or FALSE in case of an error. The
time is returned as a Unix timestamp, which is suitable for
the
date() function.
The results of this function are cached. See
clearstatcache() for more details.
This function will not work on remote files; the file to be
examined must be accessible via the server's filesystem.
Note: This function returns the time when the data
blocks of a file were being written to, that is, the time
when the content of the file was changed.
See also filectime(),
stat(), touch(),
and
getlastmod().