Shouldn't have to download and unpack a tarball to see how it's licensed.
A bit paranoid, sure, but not impossible.
Now seriously, I'm not particularly interested on this, but if it helps here are additional points of reference to at least be able to verify some integrity in case you want to try it.
SHA256:
90d7b2d632a3887bf26c10c42584ba899a3071725dae7dcddddcbab54768b54b freebsd-rustdate-0.6.1.tar.xz
Doesn't prove the absence of any malicious intent, but at least it should help prove that nothing is changing between requests (i.e. that the file I got is the same as the file you got).