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.
Note: The results of this function are cached. See clearstatcache() for more details.
Tip: As of PHP 5.0.0 this function can also be used with some URL wrappers. Refer to Appendix M for a listing of which wrappers support stat() family of functionality.
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().