I find this absolutely useless for libraries. For things like Ubuntu yes, it makes sense because you wouldn't just run a command to upgrade your os. However,

I find this absolutely useless for libraries. For things like Ubuntu yes, it makes sense because you wouldn't just run a command to upgrade your os. However, your code you usually has a bunch of libraries that depends on. When I upgrade a library I don't care when the new version came out, all I care is that doesn't have breaking changes. With semver I can get this information at a glance, calver on the other hand just says "newer version". As others have mentioned, some combination of both approaches might give an extra data point for "freshness" especially if you're managing multiple versions, but even then what's wrong with just bumping the minor/patch?