Point taken.
I always recommend and use the specific ISO8601 format
YYYY-MM-DDThh:mm:ss.sssZ
(or drop the ".sss" if not needed), and be 100% consistent about it.But you are right, I shouldn't refer to this as "use ISO8601" because it is only one of the numeous possible formats described by that spec.
No, it doesn’t, since all of the following are valid ISO 8601 representations of a date:
20210408 2021-04-07 2021-W14-1 2021W143 2021-097 2021098
(Now, consistently using any one of the ISO 8601 formats is sortable...)