Introduction
Time-zone handling in .NET 2.0 is restricted to converting between UTC and local (usually server) time. However, in order to display DateTime
correctly to users in different regions, in particular, in web applications, you need to be able to convert DateTime
between UTC (which is what you should always store in your DB) and the target time zone.
Background
The source code includes a library (basically a single class) and a sample application that shows how to use the library.
The library reads the registry for time-zone names and basic information, and uses Interop to access the Windows system calls necessary to convert between the different time zones.
Using the code
The following lines are taken from the sample application:
TimeZoneInformation[] arrTzi = TimeZoneInformation.EnumZones();
foreach (TimeZoneInformation tzi in arrTzi)
{
Console.Write("name: " + tzi.Name);
Console.WriteLine(" --- now: " + tzi.FromUniversalTime(dt));
}
Each instance of the TimeZoneInformation
class has the following useful attributes: Name
, DisplayName
, Index
, Bias
(against UTC), DaylightBias
, DaylightName
, StandardBias
, and StandardName
.
Converting between time-zones is as easy as this:
TimeZoneInformation tziLocal = TimeZoneInformation.CurrentTimeZone;
TimeZoneInformation tziRemote = TimeZoneInformation.FromIndex(10);
DateTime dt = tziLocal.ToUniversalTime(DateTime.Now);
DateTime dt2 = tziRemote.FromUniversalTime(dt);
Points of interest
I have noticed that the time-zone names change when there are Windows updates, so you do not want to rely on them. I am keeping my fingers crossed that the Index
attribute will not change.
Acknowledgements
I found the basis for my code on the internet but cannot remember where (it has been about two years ago). If you are the one whose code snippets I borrowed, drop me an email and I'll name you here!
History
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