Why isn't my local DateTime being converted to UTC?

Question

I create a local DateTime where the offset should be 00:01:00 (GMT Standard Time). However when converting to UTC it merely specifies the kind as UTC, and doesn't actually convert it.

    [Test]
    public void GivenLocalDateTime_WhenConverted_ThenBecomesUtc()
    {
        // Arrange
        var local = new DateTime(2020, 1, 1, 0, 0, 0, DateTimeKind.Local);
        var expected = new DateTime(2019, 12, 31, 23, 0, 0, DateTimeKind.Utc);

        // Act
        var result = local.ToUniversalTime();

        // Assert
        Assert.AreEqual(DateTimeOffset.Now.Offset, TimeSpan.FromHours(1)); // Passes
        Assert.AreEqual(expected.Kind, result.Kind); // Passes
        Assert.AreEqual(expected, result); // Fails

        /*
            Expected: 2019-12-31 23:00:00
            But was:  2020-01-01 00:00:00
        */
    }

I've tried several routes. Using TimeZoneInfo...

var result = TimeZoneInfo.ConvertTimeToUtc(local, TimeZoneInfo.Local);

And parsing it as a string...

var result = DateTime.Parse(local.ToString("O"), CultureInfo.InvariantCulture, DateTimeStyles.AssumeLocal | DateTimeStyles.AdjustToUniversal);

None of these work. I feel like all of these should work. What am I missing?

Answer 1

This verifies that you are currently (August) 1 hour ahead of UTC:

Assert.AreEqual(DateTimeOffset.Now.Offset, TimeSpan.FromHours(1)); // Passes

While the actual test converts a date in January when there is probably a different UTC offset. So if you have configured DST, it is expected that your test fails.