You can translate, although it can be quite difficult, and isn't really useful. In the case of Betelgeuse we don't even know its exact distance (to +/- 100 ly)

You can translate, although it can be quite difficult, and isn't really useful. In the case of Betelgeuse we don't even know its exact distance (to +/- 100 ly) or proper motion relative to Sol, so it would be a very, very rough approximation. But really the more important thing here is that such translation is quite pointless... it doesn't tell us anything meaningful. Talking about relative time only becomes meaningful when you're talking about round-trip communication, and there the meaningful part is the complete round trip, and not what moment here corresponds to a moment there.