IANA timezone style doesn't work on Windows dotnet 6.

Investigative information

I’m using a Windows function v4 using dotnet 6 on consumption tier in Japan East. Our code uses TimeZoneInfo with IANA style, but the code throws System.TimeZoneNotFoundException.

Repro steps

Create a new function on the portal. And create a new HttpTrigger function like follows:

#r "Newtonsoft.Json"
using System;
using System.Net;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Primitives;
using Newtonsoft.Json;

public static async Task<IActionResult> Run(HttpRequest req, ILogger log)
{
    log.LogInformation("C# HTTP trigger function processed a request.");
    //var timeZone = TimeZoneInfo.FindSystemTimeZoneById("Tokyo Standard Time");
    var timeZone = TimeZoneInfo.FindSystemTimeZoneById("Asia/Tokyo");
    log.LogInformation($"{timeZone}");

    string name = req.Query["name"];

    string requestBody = await new StreamReader(req.Body).ReadToEndAsync();
    dynamic data = JsonConvert.DeserializeObject(requestBody);
    name = name ?? data?.name;

    string responseMessage = string.IsNullOrEmpty(name)
        ? "This HTTP triggered function executed successfully. Pass a name in the query string or in the request body for a personalized response."
                : $"Hello, {name}. This HTTP triggered function executed successfully.";

            return new OkObjectResult(responseMessage);
}

Hit to “Run” the above code.

Expected behavior

It should be successfully finished.

Actual behavior

It throws a following exception.

2021-11-30T15:10:21.022 [Error] Executed 'Functions.HttpTrigger1' (Failed, Id=91fd9fd5-5b20-4a42-92cf-42bdf78de402, Duration=16ms)The time zone ID 'Asia/Tokyo' was not found on the local computer.

Dotnet 6 supports both IANA and Windows time zone style. So the code above should be fine. https://devblogs.microsoft.com/dotnet/date-time-and-time-zone-enhancements-in-net-6/

Known workarounds

If we use TimeZoneConverter library, it accepts IANA style even on Windows.

[kshyju]

Hi @daigok Thanks for sharing the repro information. This issue is not specific to azure functions. You will experience the same issue if you try your code in an aspnet core web api (net 6) and deploy to azure. Let me check with the team to determine whether this is a platform issue or an issue with the API itself.

cc @pragnagopa @fabiocav

[msftbot[bot]]

This issue has been automatically marked as stale because it has been marked as requiring author feedback but has not had any activity for 4 days. It will be closed if no further activity occurs within 3 days of this comment.