Date & Time Only

In .NET 6, two new types were introduced: DateOnly and TimeOnly. These are unfortunately not fully supported in serializers and typically require type conversion for use with Web APIs. Fundamentals offers serializers and type converters for these types, which are automatically hooked up in the application model.

System.Text.Json converters

Within the Fundamentals package you'll find a namespace called Json. This holds converters for serializing and deserializing both DateOnly and TimeOnly types.

using System.Text.Json;
using Cratis.Json;

var options = new JsonSerializerOptions
{
    Converters =
    {
        new DateOnlyJsonConverter(),
        new TimeOnlyJsonConverter()
    }
};

var account = new Account
{
    RegisteredDate = new DateOnly(2022, 8, 19),
    RegisteredTime = new TimeOnly(13, 37, 0)
};
var serialized = JsonSerializer.Serialize(account, options);

The output would be:

{
    "registeredDate": "2022-08-19",
    "registeredTime": "13:37:00.1200720"
}

The converter handles deserializing it correctly. Just pass in the converter factory:

using System.Text.Json;
using Cratis.Json;

var options = new JsonSerializerOptions
{
    Converters =
var options = new JsonSerializerOptions
{
    Converters =
    {
        new DateOnlyJsonConverter(),
        new TimeOnlyJsonConverter()
    }
};

var json = "{ \"registeredDate\": \"2022-08-19\", \"registeredTime\": \"13:37:00.1200720\" }";
var account = JsonSerializer.Deserialize<Account>(json, options);

Note: If you're using the Cratis Application Model, you do not have to configure this. It is automatically configured for the ASP.NET pipelines and other parts that needs it, such as the Cratis Kernel transports.

Type Converters

The .NET component model has the concept of a type converter. These are leveraged by different parts of the .NET platform, including ASP.NET when dealing with things like parameters for controllers. Out of the box, Fundamentals provides a type converter for the DateOnly and TimeOnly types. All you need to do is register them.

using System.ComponentModel;
using Cratis.Conversion;

TypeDescriptor.AddAttributes(typeof(DateOnly), new TypeConverterAttribute(typeof(DateOnlyTypeConverter)));
TypeDescriptor.AddAttributes(typeof(TimeOnly), new TypeConverterAttribute(typeof(TimeOnlyTypeConverter)));

There is a convenience method for registering these and other converters in Fundamentals:

using Cratis.Conversion;

TypeConverters.Register();

Note: If you're using the Cratis Application Model, you do not have to manually set this up. It is automatically configured at startup.

Table of Contents

Date & Time Only

System.Text.Json converters

Type Converters