Convert UTC/GMT time to local time

Question

We are developing a C# application for a web-service client. This will run on Windows XP PC\'s.

One of the fields returned by the web service is a DateTime field. Th

Answer 1

@TimeZoneInfo.ConvertTimeFromUtc(timeUtc, TimeZoneInfo.Local)

Answer 2

I'd just like to add a general note of caution.

If all you are doing is getting the current time from the computer's internal clock to put a date/time on the display or a report, then all is well. But if you are saving the date/time information for later reference or are computing date/times, beware!

Let's say you determine that a cruise ship arrived in Honolulu on 20 Dec 2007 at 15:00 UTC. And you want to know what local time that was.
1. There are probably at least three 'locals' involved. Local may mean Honolulu, or it may mean where your computer is located, or it may mean the location where your customer is located.
2. If you use the built-in functions to do the conversion, it will probably be wrong. This is because daylight savings time is (probably) currently in effect on your computer, but was NOT in effect in December. But Windows does not know this... all it has is one flag to determine if daylight savings time is currently in effect. And if it is currently in effect, then it will happily add an hour even to a date in December.
3. Daylight savings time is implemented differently (or not at all) in various political subdivisions. Don't think that just because your country changes on a specific date, that other countries will too.

Answer 3

I came across this question as I was having a problem with the UTC dates you get back through the twitter API (created_at field on a status); I need to convert them to DateTime. None of the answers/ code samples in the answers on this page were sufficient to stop me getting a "String was not recognized as a valid DateTime" error (but it's the closest I have got to finding the correct answer on SO)

Posting this link here in case this helps someone else - the answer I needed was found on this blog post: http://www.wduffy.co.uk/blog/parsing-dates-when-aspnets-datetimeparse-doesnt-work/ - basically use DateTime.ParseExact with a format string instead of DateTime.Parse

Answer 4

TimeZone.CurrentTimeZone.ToLocalTime(date);

Answer 5

In answer to Dana's suggestion:

The code sample now looks like:

string date = "Web service date"..ToString("R", ci);
DateTime convertedDate = DateTime.Parse(date);            
DateTime dt = TimeZone.CurrentTimeZone.ToLocalTime(convertedDate);

The original date was 20/08/08; the kind was UTC.

Both "convertedDate" and "dt" are the same:

21/08/08 10:00:26; the kind was local