The same way you count time on a clock. The same way the Romans and Greeks did it thousands of years ago. And they had no concept of zero.
But as you inferred, it is not necessary for WeatherFlow to change it. I already change it in my code. I probably never would have given it a second thought except I had an ATC ask me why north was reading 0 degrees.
You don’t. Compass directions are integer values. Even in super accurate GPS terms.
Not all people are in the military. There are plenty of compasses old and new alike with North being indicated as 0 degrees. I guess it is as @peter wrote a matter of taste.
I even found one with north as 360 but those are not as abundant as those with north as 0
@GaryFunk & @peter I completely agree with your instinct that wind direction should be reported as “null” or “undefined” when wind speed is zero, because without motion you can’t have direction and “0 degrees” does not mean “no direction”. One could argue that direction is “all directions” ("[0-360]") or “no directions”, but it’s certainly not the single direction known as “0°” (or “360 degrees” for Gary. Or “720 degrees” etc.).
As mentioned, that’s what we do in the apps: direction is presented as null when speed is zero. So the question is only whether we should do it at the lower level, in the data… And here I would also agree with you that we should do that. I would like to do it.
However, after discussing it here with the team, we simply can’t make it a priority. Too much other stuff to do. For now, we just need to stick with the simple rule: if speed is 0, direction is reported as 0 but is actually unknown.
PS: It is EXTREMELY COMMON in the weather industry to report direction as 0 when speed is 0. That doesn’t make it right, I’m just stating a fact 
Thank you, David. I don’t expect any suggestion from us to be a priority. We know there is much to be done.
As I pointed out, third-party developers can implement the changes now so when the firmware does change there will be no need to rush to fix the software.