Constants aren't so constant [SOLVED]

[StephenG1CMZ]

I would also suggest adding NIST_Year or something, to identify in one place which version of all the variables you have - to be accessible from a user program along with the other variables, so that a program can add "as at 2016" or whatever to the small print..

Everyone is bound to have their own additions they would like to sneak in, but I usually end up defining my own, if only whilst compatability testing.