[bcrosby95]

A missing feature is not the same thing as poor design. If you need time spans in your project it could be a fault, but every product has missing features and choosing a product that is missing features you want might be a poor decision - depending upon other tradeoffs you're making.

[pm90]

If MySQL did not have a TIME type, then I would agree with you.

The problem is that MYSQL does have such a type, and it seems to not be very useful for modern applications.

Maybe you could argue semantically that this is still a “feature” that’s missing. Perhaps. But it seems more like a defect, even if it is documented.

If arrays in Golang could only be 5 elements long (say), I think we would characterize that as a defect, even if it is well documented.

[craftinator]

It seems like poor design to me, but more so on the .NET side than MySQL side. MySQL retaining backwards compatibility is sensible, though seems a bit awkward that they don't introduce a TIME_LONG type or similar that can hold more useful ranges. .NET just mapping a time span with a wider range down to MySQL's fairly limited range seems destined to cause problems.