[Physicist]

And here's another mistake: in Earth's frame, the Tempus Fugitive receives the signal on April 2, 3000, not April 1.

[PatrickHenry]

And here's another mistake: in Earth's frame, the Tempus Fugitive receives the signal on April 2, 3000, not April 1.

I didn't check the dates. (Not geeky enough.) But seriously, a slide rule is much faster than anything else for computing gamma.

[VadeRetro]

. . . not April 1.

Just as well. It would have been taken for a joke, otherwise.