Question

The code:

var str = "91212";
DateTime.ParseExact(str, "Hmmss", System.Globalization.CultureInfo.CurrentCulture);

The error:

"91212" is not a valid DateTime

It seems c# try to use H to match 91, which is incorrect hour.

How to fix it?

Answer 1

H, according to MSDN, is interpreted as:

The hour, using a 24-hour clock from 0 to 23.

so the behaviour you are seeing is as-designed and as documented.

Could you prepend 91212 with a zero?