How do I format hours in DateTime to return 0 instead of 12?

Question

By default, the hour in a format string for a DateTime transforms 0 into 12. For example, if you have

DateTime dt = new DateTime(1999, 1, 1, 0, 0, 0);
string s = dt.ToString("h:mm:ss");

the value of s will be "12:0:0", not "0:0:0". Is there a way to get "0:00:00" instead?

Answer 1

string s = (dt.Hour >= 12 ? dt.Hour - 12 : dt.Hour).ToString() +
    dt.ToString(":mm:ss");

Apparently this was not what you were looking for. The way I read your post, you wanted a 12-hour clock that remapped "12:00" to "0:00" (some international clocks do this), which this produces. There is no format string for this behavior, so you have to create the string yourself.

You can also read more on DateTime format strings here.

Answer 2

You were close, try using this instead:

string s = dt.ToString("H:mm:ss");

Answer 3

Try

string s = dt.ToString("H:mm:ss");

Here's the reference page.

Answer 4

Instead of "h:mm:ss", use "H:mm:ss"

Answer 5

You need to use a capital H instead of the lowercase h inside the ToString method.

I.e.

DateTime dt = new DateTime(1999, 1, 1, 0, 0, 0); string s = dt.ToString("H:mm:ss");