After you have gone down to EV 0-1 at ASA 250, all the meters lose accuracy down to the reciprocity point. So I wouldn't put too much stock in a dial, as it is just a dial. Really doesn't mean a heck of a lot. For instance, I recently sold a Nikon F2S in absolute perfect condition. An F2S with a good meter can meter down to 10 seconds, and do it quite well. But even that one moved progressively closer to 1 stop off as I approached the 8-10 second range. Facing the cold reality, when it gets dark, the meter gets as blind as you do with your own eyes. No light is no light, period. It's a light meter. AFAIK, nobody has ever invented a "dark meter".
To this end, an SBC is a very fine, brittle, breakable plastic piece of oversized battery-hogging German engineering. As good as a meter gets (or got in its day). That's all there is to it. 8 hours? Throw in reciprocity into the mix and it's probably more like 8 days.
In reality, it's just a darn good meter that can see no better than you can.