Blog-UnixEpochTimeToDateTimeJsonConverter.md

using System;
using System.Text.Json;
using System.Text.Json.Serialization;

// ...

public class UnixEpochTimeToDateTimeJsonConverter : JsonConverter<DateTime>
{
    public override DateTime Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
    {
        var jsonNumber = reader.GetInt64();

        return DateTimeOffset
            .FromUnixTimeSeconds(jsonNumber)
            .UtcDateTime;
    }

    public override void Write(Utf8JsonWriter writer, DateTime value, JsonSerializerOptions options)
    {
        var unixTime = ((DateTimeOffset)value).ToUnixTimeSeconds();

        writer.WriteNumberValue(unixTime);
    }
}