An implementation of JSON converter between Unix's timestamp in milliseconds and .NET's DateTime for Json.NET

Blog_JsonNet_UnixMillisDateTimeConverter.cs

public class UnixMillisDateTimeConverter : JsonConverter
{
    public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
    {
        if (value == null)
        {
            writer.WriteNull();
            return;
        }

        var dateTime = (DateTime)value;
        var offset = new DateTimeOffset(dateTime);
        var unixTimestamp = offset.ToUnixTimeMilliseconds();
        writer.WriteValue(unixTimestamp);
    }

    public override object ReadJson(JsonReader reader, Type type, object value, JsonSerializer serializer)
    {
        if (reader.Value == null)
        {
            return type == typeof(DateTime?) ? (object)null : DateTime.MinValue;
        }

        long epoch;
        if (reader.ValueType == typeof(long))
        {
            epoch = (long)reader.Value;
        }
        else
        {
            epoch = long.Parse((string)reader.Value);
        }

        var offset = DateTimeOffset.FromUnixTimeMilliseconds(epoch);
        return offset.DateTime;
    }

    public override bool CanConvert(Type type)
    {
        return type == typeof(DateTime) || type == typeof(DateTime?);
    }
}