Convert UTC time to local time using Nodatime

问题:

I have been provided a time in this format "ddMMyyHHmmss". I know the time is in UTC format. I would like to use the NodaTime library to convert this to my local timezone but I can't seem to figure it out. My local timezone target is to be New Zealand.

Here's what I have tried:

 var pattern = LocalDateTimePattern.CreateWithInvariantCulture("ddMMyyHHmmss");

 var parseResult = pattern.Parse(utcDateTime);
 if (!parseResult.Success)
 {
     throw new InvalidDataException("Invalid time specified " + date + time);
 }

 var timeZone = DateTimeZoneProviders.Bcl["New Zealand Standard Time"];

 var zone = new ZonedDateTime(
                  localDateTime, 
                  timeZone, 
                  timeZone.GetUtcOffset(SystemClock.Instance.Now));


 return new DateTime(zone.ToInstant().Ticks);

回答1:

// Since your input value is in UTC, parse it directly as an Instant.
var pattern = InstantPattern.CreateWithInvariantCulture("ddMMyyHHmmss");
var parseResult = pattern.Parse("150713192900");
if (!parseResult.Success)
    throw new InvalidDataException("...whatever...");
var instant = parseResult.Value;

Debug.WriteLine(instant);  // 2013-07-15T19:29:00Z

// You will always be better off with the tzdb, but either of these will work.
var timeZone = DateTimeZoneProviders.Tzdb["Pacific/Auckland"];
//var timeZone = DateTimeZoneProviders.Bcl["New Zealand Standard Time"];

// Convert the instant to the zone's local time
var zonedDateTime = instant.InZone(timeZone);

Debug.WriteLine(zonedDateTime);
  // Local: 7/16/2013 7:29:00 AM Offset: +12 Zone: Pacific/Auckland

// and if you must have a DateTime, get it like this
var bclDateTime = zonedDateTime.ToDateTimeUnspecified();

Debug.WriteLine(bclDateTime.ToString("o"));  // 2013-07-16T07:29:00.0000000