asp.neyt cpre serialization error he JSON value could not be converted to System.DateTime. code example
Example: The JSON value could not be converted to System.DateTime
your date value in your JSON isn't correct. should be
2019-01-06T17:16:40
Most parsers use ISO 8601
You can use
new Date(stringValue).toISOString()
Then your post will work using the correct date format :)