public string TranslateToCET(string d)
{
    var dateIn = DateTimeOffset.Parse(d);

    foreach (var tz in TimeZoneInfo.GetSystemTimeZones())
    {
        if (tz.DisplayName.Contains("Stockholm"))
        {
            var dateOut = TimeZoneInfo.ConvertTime(dateIn, tz);
            return dateOut.ToString("yyyy-MM-ddTHH:mm:ss");
        }
    }

    throw new Exception("Could not find Stockholm TimeZoneInfo!");
}