c# - AM/PM to TimeSpan

Question

I want to achieve the converse of this, that is, I want to convert a string with format hh:mm tt to a TimeSpan with zeroed seconds.

For example, 09:45 pm is converted to 21:45:00.

Answer 1

The simplest approach would probably be to parse it as a DateTime using DateTime.ParseExact, and then use the TimeOfDay to exact the TimeSpan.

DateTime dateTime = DateTime.ParseExact(text,
                                    "hh:mm tt", CultureInfo.InvariantCulture);
TimeSpan span = dateTime.TimeOfDay;

It's odd to see a leading 0 on a number of hours when you're also specifying an am/pm designator though. You might want "h" instead of "hh" in the format string, to allow "9:45 pm" instead of "09:45 pm".

(I'd also argue that it's a strange use of TimeSpan in the first place, but then the .NET date/time types are somewhat messed up in my view. I'd recommend using Noda Time, but I'm biased :)