System.Text.Json serialize accurate DateTime incorrectly! #10070
Description
aspnetcore3.0 preview5 using System.Text.Json as input- and outputformatter:
if DateTime is too accurate (sqlserver datetime2), it will serialize it to invalid format like: 2019-05-08T00:00:5406760219
This kind of result could not even be recognized by DateTime.Parse.
I think it should be 2019-05-08T00:00:54.06760219 (with a dot between seconds number and others) which can be parsed by DateTime class.
