OrchardCMS/OrchardCore · error · JsonException

Unable to convert " " to DateTime.

Error message

Unable to convert "{stringValue}" to DateTime.

What it means

The JSON token could not be parsed as a DateTime: Utf8JsonReader.TryGetDateTime failed (token is not an ISO 8601 string) and the fallback DateTime.TryParse on the raw string also failed. This fires when the JSON contains a date in a non-ISO format (e.g. 'dd/MM/yyyy') or a non-date value where a DateTime is expected.

Solutions

1. Serialize dates as ISO 8601 strings (yyyy-MM-ddTHH:mm:ssZ), the format this converter writes
2. Add a CultureInfo/DateTimeStyles-specific parse branch to the converter for the legacy format in use
3. Correct the producing side to emit a DateTime-compatible string instead of an arbitrary format

When it happens

Trigger: Thrown at src/OrchardCore/OrchardCore.Abstractions/Json/Serialization/DateTimeJsonConverter.cs:26 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of OrchardCMS/OrchardCore@4306c0717f (2026-09-13). Data as JSON: /api/errors/52087390caeb98d1. Report an issue: GitHub.

Appendix: source

Thrown at src/OrchardCore/OrchardCore.Abstractions/Json/Serialization/DateTimeJsonConverter.cs:26

{
    public static readonly DateTimeJsonConverter Instance = new();

    public override DateTime Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
    {
        if (typeToConvert != typeof(DateTime))
        {
            throw new ArgumentException("Unexpected type to convert.", nameof(typeToConvert));
        }

        if (!reader.TryGetDateTime(out var value))
        {
            var stringValue = reader.GetString();
            if (DateTime.TryParse(stringValue, out value))
            {
                return value;
            }

            throw new JsonException($"Unable to convert \"{stringValue}\" to DateTime.");
        }

        return value;
    }

    public override void Write(Utf8JsonWriter writer, DateTime value, JsonSerializerOptions options)
        => writer.WriteStringValue(value.ToString("yyyy-MM-ddTHH:mm:ssZ", CultureInfo.InvariantCulture));
}

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