Comment by friendzis

> For example you cannot represent wall clock which is a problem for dates in the future as time zone changes

While I understand this particular frustration, in my book it is a feature. The critique usually devolves into hypothetical scenarios, e.g. changes to DST. "I want to be able to specify 14:00 in four years in Absurdistan local time, whatever that is in relation to UTC, but cannot!" is a common critique of ISO 8601. However, if you go a little bit further with hypotheticals, Absurdistan might add some overseas territories, might join some alliance and change timezone/DST, etc.

When you think about the problem statement, definition of "local time" itself may change, therefore it is impossible to specify "local time" in the future without *exhaustively* defining all possible changes.

So you either define number of atomic ticks (TAI) in the future and resolve local time at the time of use or specify some static time and resolve it to local time at the time of use.