Sets access and modification time of file
touch ( string $filename [, int $time = time() [, int $atime ]] ) : bool
The name of the file being touched.
The touch time. If time is not supplied, the current system time is used.
If present, the access time of the given filename is set to the value of atime. Otherwise, it is set to the value passed to the time parameter. If neither are present, the current system time is used.
Returns TRUE on success or FALSE on failure.
access time and modification time set to current time
access time and modification time set to one hour in the past
access time set to two hours in the past and modification time set to one hour in the past