Universal Time vs UTC Time in Dates

[mihalybaci]

It would appear that the decision has already been made to end leapseconds.

`DateTime` arithmetic on `Microsecond` (or smaller) scale

@Oscar_Smith brought up an argument for why it shouldn’t error - namely, imagine using DateTime and its arithmetic as the time variable in an ODE. DateTime shouldn’t be used for time intervals (UTM though is there for that); nor then I think ODEs. DateTime is for ISO 8601 timestamps, as documented; I guess for 8601-1 (going forward, not yet documented as such I believe), as opposed to 8601-2: https://www.isotc154.org/posts/2019-08-27-introduction-to-the-new-8601/ ISO 8601 is now a family…