JsonDateTimeSerializationMode
Specifies whether a DateTime object represents a local time, a Coordinated Universal Time (UTC), or is not specified as either local time or UTC.
Local = 0
The time represented is local time.
RoundtripKind = 3
Preserves the DateTimeKind field of a date when a DateTime object is converted to a string and the string is then converted back to a DateTime object.
Unspecified = 2
The time represented is not specified as either local time or Coordinated Universal Time (UTC).
Utc = 1
The time represented is UTC.