private enum TimeSpanElement
    {
        Millisecond,
        Second,
        Minute,
        Hour,
        Day
    }   
public static string ToFriendlyDisplay(this TimeSpan timeSpan, int maxNrOfElements = 3)
    {
        maxNrOfElements = Math.Max(Math.Min(maxNrOfElements, 5), 1);
        var parts = new[]
                        {
                            Tuple.Create(TimeSpanElement.Day, timeSpan.Days),
                            Tuple.Create(TimeSpanElement.Hour, timeSpan.Hours),
                            Tuple.Create(TimeSpanElement.Minute, timeSpan.Minutes),
                            Tuple.Create(TimeSpanElement.Second, timeSpan.Seconds),
                            Tuple.Create(TimeSpanElement.Millisecond, timeSpan.Milliseconds)
                        }
                                    .SkipWhile(i => i.Item2 <= 0)
                                    .Take(maxNrOfElements);

        return string.Join(", ", parts.Select(p => string.Format("{0} {1}{2}", p.Item2, p.Item1, p.Item2 > 1 ? "s" : string.Empty)));
    }