title: R file.mtime() extremely poor precision on Mac OS and Windows 7
body: <p>On Windows 7 and Mac OS 10.12.2 (with R 3.3.2), it appears that <code>file.mtime()</code> severely rounds or truncates timestamps. I verified that <code>file.create("my_file.txt"); print(as.numeric(file.mtime("my_file.txt")), digits = 22)</code> prints out several digits past the decimal on Linux, but everything past the decimal disappears on Windows 7 for the same <code>my_file.txt</code>. The behavior for Mac OS 10.12.2 is similar to that of Windows 7. Is there a platform-independent way to get precise file timestamps in R?</p>