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.
Замечание: The results of this function are cached. See clearstatcache() for more details.
Замечание: This function will not work on remote files as the file to be examined must be accessible via the servers filesystem.
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.