TimeSpan to friendly string library (C#)

Not a fully featured implementation, but it should get you close enough.

DateTime dtNow = DateTime.Now;
DateTime dtYesterday = DateTime.Now.AddDays(-435.0);
TimeSpan ts = dtNow.Subtract(dtYesterday);

int years = ts.Days / 365; //no leap year accounting
int months = (ts.Days % 365) / 30; //naive guess at month size
int weeks = ((ts.Days % 365) % 30) / 7;
int days = (((ts.Days % 365) % 30) % 7);

StringBuilder sb = new StringBuilder();
if(years > 0)
{
    sb.Append(years.ToString() + " years, ");
}
if(months > 0)
{
    sb.Append(months.ToString() + " months, ");
}
if(weeks > 0)
{
    sb.Append(weeks.ToString() + " weeks, ");
}
if(days > 0)
{
    sb.Append(days.ToString() + " days.");
}
string FormattedTimeSpan = sb.ToString();

In the end, do you really need to let someone know a document is going to expire exactly 1 year, 5 months, 2 weeks, and 3 days from now? Can't you get by with telling them the document will expire over 1 year from now, or over 5 months from now? Just take the largest unit and say over n of that unit.

There is now also the Humanizer project that looks very interesting that can do this and way more.

I just stumbled upon this question because I wanted to do a similar thing. After some googling I still didn't find what I wanted: display a timespan in a sort of "rounded" fashion. I mean: when some event took several days, it doesn't always make sense to display the milliseconds. However, when it took minutes, it probably does. And in that case, I don't want 0 days and 0 hours to be displayed. So, I want to parametrize the number of relevant timespan parts to be displayed. This resulted in this bit of code:

public static class TimeSpanExtensions
{
    private enum TimeSpanElement
    {
        Millisecond,
        Second,
        Minute,
        Hour,
        Day
    }

    public static string ToFriendlyDisplay(this TimeSpan timeSpan, int maxNrOfElements)
    {
        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)));
    }
}

Example (LinqPad):

new TimeSpan(1,2,3,4,5).ToFriendlyDisplay(3).Dump();
new TimeSpan(0,5,3,4,5).ToFriendlyDisplay(3).Dump();

Displays:

1 Day, 2 Hours, 3 Minutes
5 Hours, 3 Minutes, 4 Seconds

Suits me, see if it suits you.