Re: Trivial question: how to avoid confusing sec, min, hour and day in a program?

[ldries46 <bertus.dries@planet.nl>]

Op 6-9-2021 om 15:43 schreef J-P. Rosen:
> Le 06/09/2021 à 15:06, ldries46 a écrit :
>>> If calculations are involved, they are performed in SI, because 
>>> otherwise you need factors in all formulae. And SI means no mm, but 
>>> m, no km/h, but m/s etc.
>> Sorry but It should perhaps be so but it is not. Programs made 
>> primarily for Aircraft engineering (f.i. CATIA 5/6) do use mm and 
>> your velocity clock in your car shows km/h and it registers the 
>> distance in km (in England and the USA mph and miles) In aircraft the 
>> Speed is often still measured in Knots (Nautical miles per hour). 
>> Maybe French aircraft will possibly show km/h. It is to hazardous to 
>> change this
>
> Do not confuse computations with input/output. I agree with Dmitry, 
> all computations should be performed in SI, with a (user selectable) 
> choice of units for input and display.
>
What I tried to say is just what J-P Rosen says. But in my experience 
(41 years in aircraft engineering) that is not so, every time you have 
to realise what the system your working with and you are forced to even 
use systems parallel. One of the points I made the mechanical 
engineering which often uses cm has standard profiles using mm HE110B is 
100mm high. That is the reason that I ask for a package which solves 
this problem for once and always and still gives the user the 
possibility to use all kind of dimesions