TryParseExact of DateTimeOffset.MinValue fails

[alexdrl]

Why this code fails for both the last parts of the "test"?

https://dotnetfiddle.net/QM5fBn

The code is quite simple

using System;
using System.Globalization;

public class Program
{
	private static readonly string[] _acceptableFormats = new[]{"yyyy-MM-dd'T'HH:mm:ss.FFFFFFFK", "yyyy-MM-dd' 'HH:mm:ss.FFFFFFFK", "yyyy-MM-dd'T'HH:mm:ssK", "yyyy-MM-dd' 'HH:mm:ssK", "yyyy-MM-dd'T'HH:mm:ss", "yyyy-MM-dd' 'HH:mm:ss", "yyyy-MM-dd'T'HH:mm", "yyyy-MM-dd' 'HH:mm", "yyyy-MM-dd'T'HH", "yyyy-MM-dd' 'HH", "yyyy-MM-dd", "yyyy-MM-dd", "yyyyMMdd", "yyyy-MM", "yyyy"};
	
	public static void Main()
	{
		Console.WriteLine("Hello World");
		var canParseValue = DateTimeOffset.TryParseExact("0001-01-01T00:00:00", _acceptableFormats, CultureInfo.InvariantCulture, DateTimeStyles.None, out DateTimeOffset dateTimeResult);
		Console.WriteLine(canParseValue);
		var canParseValue2 = DateTimeOffset.TryParseExact("0001-01-01T01:00:00", _acceptableFormats, CultureInfo.InvariantCulture, DateTimeStyles.None, out DateTimeOffset dateTimeResult2);
		Console.WriteLine(canParseValue2);
		var canParseValue3 = DateTimeOffset.TryParseExact(DateTimeOffset.MinValue.ToString(), _acceptableFormats, CultureInfo.InvariantCulture, DateTimeStyles.None, out DateTimeOffset dateTimeResult3);
		Console.WriteLine(canParseValue3);
		var canParseValue4 = DateTimeOffset.TryParseExact(DateTime.MinValue.ToString(), _acceptableFormats, CultureInfo.InvariantCulture, DateTimeStyles.None, out DateTimeOffset dateTimeResult4);
		Console.WriteLine(canParseValue4);
	}
}

[Clockwork-Muse]

// Outputs 01/01/0001 00:00:00 +00:00
Console.WriteLine(DateTimeOffset.MinValue.ToString());

The string you're working with isn't on the list of acceptable formats. You either need to add the invariant culture formats to the list of acceptable formats, or explicitly format the source string to one you expect.

(separately, I'm annoyed the InvariantCulture doesn't use an ISO format, but that would be a massive breaking change....)

[alexdrl]

Yeah and what about the latest scenario with DateTime.MinValue.ToString()? It outputs 01/01/0001 00:00:00

[Clockwork-Muse]

.... and that's not on the list of acceptable formats either.