> timezone setting as a part of user content type
Users will travel and forget to update the setting. Could be used to provide a default value for a timezone input, though.
Better might be to use geolocation to provide a default value for a timezone input, but then we depend on such a service. And cross-timezone VPNs may confuse it, so users will have to verify the value. I think that no matter how this is implemented, there must be a way for the user to set the timezone manually.
Don't we need the same thing for the Time type? And even Date, since internally it uses a timestamp AFAIR, which could lead to date errors if the timezone is wrong (in edge cases).