static DateTime ConvertFromUnixTimestamp(double timestamp)
{
    DateTime origin = new DateTime(1970, 1, 1, 0, 0, 0, 0);
    return origin.AddSeconds(timestamp);
}


static double ConvertToUnixTimestamp(DateTime date)
{
    DateTime origin = new DateTime(1970, 1, 1, 0, 0, 0, 0);
    TimeSpan diff = date - origin;
    return Math.Floor(diff.TotalSeconds);
}