String '04/28/2021 04:25p' was not recognized as a valid DateTime-CodePudding

I'm getting data from a third-party API. I'm receiving a date string like this "04/28/2021 04:25p". Can't convert this string into a DateTime value.

I've tried the following:

var dateValue = DateTime.ParseExact(
    "04/28/2021 04:25p", 
    "MM/dd/yyyy HH:mm tt", 
    new CultureInfo("en-US"));

What is it I'm missing here?

Update: I've used double quotes in my code, forgot to put double-quote here. Updated the question now.

CodePudding user response：

You can use a single letter AM/PM-designator, but then it has to be uppercase:

var dateValue = DateTime.ParseExact(
    "04/28/2021 04:25p".ToUpper(), 
    "MM/dd/yyyy hh:mmt", 
    new CultureInfo("en-US"));

Otherwise you need to add the 'm':

var dateValue = DateTime.ParseExact(
    "04/28/2021 04:25p" "m", 
    "MM/dd/yyyy hh:mmtt", 
    new CultureInfo("en-US"));

The third option is to code your own CultureInfo, where DateTimeFormat.AMDesignator is 'm' and DateTimeFormat.PMDesignator is 'p':

public class SingleLetterDesignatorCultureInfo : CultureInfo
{
    private DateTimeFormatInfo dateTimeFormatInfo;
    
    public SingleLetterDesignatorCultureInfo():base(CultureInfo.InvariantCulture.Name)
    {
        dateTimeFormatInfo = base.DateTimeFormat;
        dateTimeFormatInfo.PMDesignator = "p";
        dateTimeFormatInfo.AMDesignator = "a";
    }
        
    public override DateTimeFormatInfo DateTimeFormat 
    {
        get => dateTimeFormatInfo;
        set => base.DateTimeFormat = value;
    }
}

var dateValue = DateTime.ParseExact(
    "04/28/2021 04:25p", 
    "MM/dd/yyyy hh:mmtt", 
    new SingleLetterDesignatorCultureInfo());

CodePudding user response：

Firstly, use double-quotes. Secondly, you can stick an "m" at the end of the input to help with the formatting.

string inputPlusM = "04/28/2021 04:25p"   "m";
var dt = DateTime.ParseExact(inputPlusM, "MM/dd/yyyy hh:mmtt", new System.Globalization.CultureInfo("en-US") );