e file modification times with a granularity
of two seconds.  If a file is less than two seconds newer than the
entry in the archive, Ant will not consider it newer.</p>

<p>The <code>whenmanifestonly</code> parameter controls what happens when no
files, apart from the manifest file, or nested services, match.
If <code>skip</code>, the JAR is not created and a warning is issued.
If <code>fail</code>, the JAR is not created and the build is halted with an error.
If <code>create</code>, (default) an empty JAR