Convert datetime-format from RFC1123 to DateTime-Object

Question

I'm on to convert the RFC1123-dateformat to DateTime-Object and vice versa. The DateTime-Object to RFC-date-string works perfectly but since I'm living in Germany (MEZ- Timezone) I get wrong results.

So once, here is my class for converting:

public interface IRFCDate
{
    DateTime ToDateTime();
}

public class RFCDate : IRFCDate
{
    private string dateString { get; set; } = null;
    private DateTime? dateObject { get; set; } = null;

    public DateTime ToDateTime()
    {
        if (dateObject.HasValue) return dateObject.Value;

        string regexPattern = @"[a-zA-Z]+, [0-9]+ [a-zA-Z]+ [0-9]+ [0-9]+:[0-9]+:[0-9]+ (?<timezone>[a-zA-Z]+)";
        Regex findTimezone = new Regex(regexPattern, RegexOptions.Compiled);

        string timezone = findTimezone.Match(dateString).Result("${timezone}");
        string format = $"ddd, dd MMM yyyy HH:mm:ss {timezone}";

        dateObject = DateTime.ParseExact(dateString, format, CultureInfo.InvariantCulture);
        return dateObject.Value;
    }
    public IRFCDate From(IConvertible value)
    {
        if (value is string)
            dateString = value.ToString();
        else if (value is DateTime)
            dateObject = (DateTime)value;
        else
            throw new NotSupportedException($"Parametertype has to be either string or DateTime. '{value.GetType()}' is unsupported.");
        return this;
    }
}

my Xunit-Testcase looks like this:

[Fact]
public void StringToDateTime()
{
    DateTime expectedValue = new DateTime(2001, 1, 1);
    string RFCDatestring = "Mon, 01 Jan 2001 00:00:00 GMT";
    DateTime actualValue = RFCDatestring.To<DateTime>();
    Assert.Equal(expectedValue, actualValue); 
}

To in this case calls

return new RFCDate().From(@this).ToDateTime();

So the result when executing my testcase is:

Assert.Equal() Failure

Expected: 2001-01-01T00:00:00.0000000

Actual: 2001-01-01T01:00:00.0000000+01:00

Someone has any ideas how to fix this? The actual value should be 00:00 o'clock instead of 1 o'clock.

Answer 1

Okay I seen that I made a mistake: I need to set the timezone to CET instead of GMT, since I'm in Germany which is CET (or GMT+1). So the function is correct.