function FileModification(const FileName: String): DateTime
The FileModification function returns the last modification date and time of the file input parameter. The return value is a DateTime value.
The specified file name should contain an absolute path. Relative paths are permitted, but they rely on the current working directory. The current working directory is a per-process setting and is not reliable in a multi-threaded setting like the web server.
Examples
X := FileModification('C:\temp\test.html'); // X is 1604515489696, or '11/4/2020 1:44 PM'