C# + Format TimeSpan

Question

I am trying to format a TimeSpan element in the format of \"[minutes]:[seconds]\". In this format, 2 minutes and 8 seconds would look like \"02:08\". I have tried a variety

Answer 1

NOTE: This answer applies to .NET 4.0 only.

The colon character is a literal and needs to be wrapped in single quotes:

duration.ToString("mm':'ss")

From the MSDN documentation:

The custom TimeSpan format specifiers do not include placeholder separator symbols, such as the symbols that separate days from hours, hours from minutes, or seconds from fractional seconds. Instead, these symbols must be included in the custom format string as string literals.

Answer 2

you could always do:

string.Format("{0}:{1}", duration.Minutes, duration.Seconds);

Answer 3

Custom formatting of System.TimeSpan was added in .Net 4, so you can now do the following:

string.Format("{0:mm\\:ss}", myTimeSpan);

(UPDATE) and here is an example using C# 6 string interpolation:

$"{myTimeSpan:hh\\:mm\\:ss}"; //example output 15:36:15

In short you now need to escape the ":" character with a "\" (which itself must be escaped unless you're using a verbatim string).

This excerpt from the MSDN Custom TimeSpan Format Strings page explains about escaping the ":" and "." charecters in a format string:

The custom TimeSpan format specifiers do not include placeholder separator symbols, such as the symbols that separate days from hours, hours from minutes, or seconds from fractional seconds. Instead, these symbols must be included in the custom format string as string literals. For example, "dd.hh:mm" defines a period (.) as the separator between days and hours, and a colon (:) as the separator between hours and minutes.

Answer 4

For some mysterious reason TimeSpan never got the ToString() overloads that support formatting until .NET 4.0. For earlier releases, as long as it is positive, you can hijack DateTime.ToString():

TimeSpan ts = new TimeSpan(0, 2, 8);
string s = new DateTime(ts.Ticks).ToString("mm:ss");