@thomasfuchs @mattl @trav_stone if they implemented their ISO8601 library properly it's not a problem because you can just add a + - and use more digits.

The only issue seems to be the number of digits sent or received has to be fixed ahead of time which would avoid buffering issues when someone sends a thousand digit date. Given the capacity of 32 or 64 bit encodings of date time to allow more years I think they could have made the year part more capacious by default with YY*