*NIX Epoch integer converter for DateTime

UnixDateTimeConverter.cs

using System;
using Newtonsoft.Json;
using Newtonsoft.Json.Converters;
    
public class UnixDateTimeConverter : DateTimeConverterBase
{
    /// <summary>
    /// Reads the JSON representation of the object.
    /// </summary>
    /// <param name="reader">The <see cref="JsonReader"/> to read from.</param>
    /// <param name="objectType">Type of the object.</param>
    /// <param name="existingValue">The existing property value of the JSON that is being converted.</param>
    /// <param name="serializer">The calling serializer.</param>
    /// <returns>The object value.</returns>
    public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
    {
        if (reader.TokenType != JsonToken.Integer)
            throw new Exception(string.Format("Unexpected token parsing date. Expected Integer, got {0}.", reader.TokenType));

        var unixTime = (long)reader.Value;
        var epoch = new DateTime(1970, 1, 1, 0, 0, 0, 0, DateTimeKind.Utc).AddSeconds(unixTime);

        return epoch;
    }

    /// <summary>
    /// Writes the JSON representation of the object.
    /// </summary>
    /// <param name="writer">The <see cref="JsonWriter"/> to write to.</param>
    /// <param name="value">The value.</param>
    /// <param name="serializer">The calling serializer.</param>
    public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
    {
        var epoch = new DateTime(1970, 1, 1, 0, 0, 0, 0);
        var dateTime = ((DateTime)value).ToUniversalTime().Subtract(epoch);
        var unixTime = (long)Math.Floor(dateTime.TotalSeconds);

        writer.WriteValue(unixTime);
    }
}