public static String FormatToSimpleSeconds(this TimeSpan timeSpan)
{
int minutes = (int)Math.Floor(Math.Abs(timeSpan.TotalSeconds) % 3600 / 60);
int seconds = (int)Math.Floor(Math.Abs(timeSpan.TotalSeconds) % 3600 % 60);
return String.Format("{0}:{1:D2}", minutes, seconds);
}
}