UTC to local timezone
From http://stackoverflow.com/questions/16674008/nodatime-conversions-part-2-how-to
// Note: the DateTime here must have a "Kind" of Utc.
public static DateTime UTCtoLocal(this DateTime dateTime)
{
Instant instant = Instant.FromDateTimeUtc(dateTime);
IDateTimeZoneProvider timeZoneProvider = DateTimeZoneProviders.Tzdb;
var usersTimezoneId = "Europe/London"; //just an example
var usersTimezone = timeZoneProvider[usersTimezoneId];
var usersZonedDateTime = instant.InZone(usersTimezone);
return usersZonedDateTime.ToDateTimeUnspecified();
}