Tbh, half of my life I handled them on a financial platform which couldn’t care less of the subj list or standards. It has just ‘wall date’ like yyyy-mm-dd and

Tbh, half of my life I handled them on a financial platform which couldn’t care less of the subj list or standards. It has just ‘wall date’ like yyyy-mm-dd and ‘wall time’ strictly in 00:00:00-23:59:59 range, without a timezone. Two separate types. Never encountered of even heard of any time-related bug there. I find this simplified date/time very useful, unless you have to manage “continuous and/or real” time somehow. 99% of applications are okay with it, because they’re facing users with exactly the same mental model. Also, albeit not correct scientifically, it reflects many developers’ mental model as well. This is much better than a model that just doesn’t match, which is a world of pain. Someone adds 86400 but it’s the same day, good luck debugging it. I don’t think this is a cryptographic-level issue.