Tasks use some rfc3339nano timestamps in a few places. #12280 is related to a run's startedAt and finishedAt values not matching swagger, because the type is defined as date-time in swagger but rfc3339nano doesn't match.

Dashboards' createdAt and updatedAt have the same issue; see #12298.

There may be other places than those two, but those are the only two outstanding issues I know of.

To fix this generally, we should have a swagger type that is capable of displaying subsecond precision.

Note, one drawback of the default rfc3339nano formatting:

The RFC3339Nano format removes trailing zeros from the seconds field and thus may not sort correctly once formatted.

FWIW, flux has a workaround to avoid removing trailing zeros: https://github.com/influxdata/flux/blob/16950c44f1433dd34f656a4128adeed73d270fcc/values/time.go#L52-L62

If we decide that sortability is a property worth keeping, we could find a way to standardize on what flux is doing there for printing out timestamps.