.net – Windows XP上的DateTime.ToLocalTime

On Windows XP systems,the ToLocalTime
method recognizes only the current
adjustment rule when converting from
UTC to local time. As a result,
conversions for periods before the
current adjustment rule came into
effect may not accurately reflect the
difference between UTC and local time.

我正在开发Windows 7,但部署到混合环境.如何提供与ToLocalTime的Windows 7行为相匹配的一致,正确的实现？

编辑

我跑了一个测试：

static void Main()
{
    // 8 AM in July,UTC. That would have been DST,so 3 AM CDT.
    var dstDate = new DateTime(2010,7,1,8,DateTimeKind.Utc);

    // 8 AM in December,UTC. Not DST,so 2 AM CST.
    var nonDstDate = new DateTime(2010,12,DateTimeKind.Utc);

    Log("DST Date ToLocalTime: " + dstDate.ToLocalTime());
    Log("DST Date ConvertTimeFromUtc: " + ConvertTimeFromUtc(dstDate));
    Log("Expected: 3 AM July 1 2010");

    Log(string.Empty);

    Log("Non-DST Date ToLocalTime: " + nonDstDate.ToLocalTime());
    Log("Non-DST Date ConvertTimeFromUtc: " + ConvertTimeFromUtc(nonDstDate));
    Log("Expected: 2 AM December 1 2010");

    Log(string.Empty);

    Log("Date ToLocalTime Kind: " + dstDate.ToLocalTime().Kind);
    Log("Date ConvertTimeFromUtc Kind: " + ConvertTimeFromUtc(dstDate).Kind);
}

private static void Log(string message)
{
    Console.WriteLine(message);
}

private static DateTime ConvertTimeFromUtc(DateTime utcDateTime)
{
    return
        DateTime.SpecifyKind(
            TimeZoneInfo.ConvertTimeFromUtc(
                utcDateTime,TimeZoneInfo.FindSystemTimeZoneById(TimeZoneInfo.Local.Id)),DateTimeKind.Local);
}

XP Pro 32位,SP3(作为VM)和Windows 7 Enterprise 64位的结果相同：

DST Date ToLocalTime: 7/1/2010 3:00:00 AM
DST Date ConvertTimeFromUtc: 7/1/2010 3:00:00 AM
Expected: 3 AM July 1 2010

Non-DST Date ToLocalTime: 12/1/2010 2:00:00 AM
Non-DST Date ConvertTimeFromUtc: 12/1/2010 2:00:00 AM
Expected: 2 AM December 1 2010

Date ToLocalTime Kind: Local
Date ConvertTimeFromUtc Kind: Local

文档错了吗？我可以简单地拨打ToLocalTime吗？

编辑2

我们在一个真正的XP系统(不是VM)上运行它,并在那里得到相同的结果.我的测试用例是否正确？任何人都可以提供结果会有所不同的情况吗？