Blazor Time Zone Kit

Summary

This is a class library as a NuGet package for Blazor browser application.

This package provides system time zones set, and local time zone initialization, for Blazor browser application.

Note

At this time, the version of Blazor is v.0.8.0 or before, those doesn't contain any time zone info, and local time zone is always UTC wherever.

See also:

• Blazor Issue #663 - TimeZone issues related to Mono?
• Blazor Issue #1166 - DateTime always displays as UTC
• Mono Issue #6368 - WebAssembly: Missing Timezone implementation

How to install and use it?

Step.1 - Install this package.

> dotnet add package Toolbelt.Blazor.TimeZoneKit

Step.2 - call UseLocalTimeZone() extension method in Configure() method of startup class.

...
using Toolbelt.Blazor.Extensions.DependencyInjection;

public class Startup
{
    ...
    public void Configure(IComponentsApplicationBuilder app)
    {
        app.UseLocalTimeZone();
    ...

That's all!

How does it work?

There is no magic.

This library contains all the system time zone information as a C# code.
(see: "TimeZoneKit.CreateSystemTimeZones.cs")

And, this library also contains mapping information for converting IANA time zone names to .NET time zone IDs.
(see: "TimeZoneKit.IANAtoTZIdMap.cs")

UseLocalTimeZone() extension method in this library invokes "Intl.DateTimeFormat().resolvedOptions().timeZone" JavaScript code to get the current time zone name (IANA name) on the web browser.

UseLocalTimeZone() extension method also set up the system time zone set and local time zone information by accessing undocumented / non public members in System.TimeZoneInfo class.

Note

• WARNING - This library accesses private members of System.TimeZoneInfo using the "Reflection" .NET API, so it may break in future .NET runtime (mono.wasm) release.
• In my test case, this package increased the size of the sample Blazor browser application content by 154 KB. (by 20KB gzip transfer.)

Release Note

• v.3.0.0 - BREAKING CHANGE: Support Blazor v.0.8.0 (not compatible with v.0.7.0 or before.)
• v.2.1.0
  • Blazor v.0.6.0 support - it was signed strong name.
  • Update time zone information
    • Morocco Standard Time
    • Namibia Standard Time
    • Fiji Standard Time
• v.2.0.0 - BREAKING CHANGE: Fix namespace of TimeZoneKitExtension class.
• v.1.0.0 - 1st release.

License

Mozilla Public License Version 2.0