How can I String.Format a TimeSpan object with a custom format in .NET?

Question

What is the recommended way of formatting TimeSpan objects into a string with a custom format?

Answer 1

Here is my extension method:

public static string ToFormattedString(this TimeSpan ts)
{
    const string separator = ", ";

    if (ts.TotalMilliseconds < 1) { return "No time"; }

    return string.Join(separator, new string[]
    {
        ts.Days > 0 ? ts.Days + (ts.Days > 1 ? " days" : " day") : null,
        ts.Hours > 0 ? ts.Hours + (ts.Hours > 1 ? " hours" : " hour") : null,
        ts.Minutes > 0 ? ts.Minutes + (ts.Minutes > 1 ? " minutes" : " minute") : null,
        ts.Seconds > 0 ? ts.Seconds + (ts.Seconds > 1 ? " seconds" : " second") : null,
        ts.Milliseconds > 0 ? ts.Milliseconds + (ts.Milliseconds > 1 ? " milliseconds" : " millisecond") : null,
    }.Where(t => t != null));
}

Example call:

string time = new TimeSpan(3, 14, 15, 0, 65).ToFormattedString();

Output:

3 days, 14 hours, 15 minutes, 65 milliseconds