CsvHelper library not able to parse datetime

Question

I am using the CsvHelper library to parse CSV files into an object list.

I have added the datetime format to the class as yyyy-MM-dd hh:mm:ss t but I'm getting an error while parsing. The date is in the following format:

public class Claim
{
    [Name("Name")]
    public string Name{ get; set; }
    [Name("Number")]
    public string Number{ get; set; }
    [Name("Date")]
    [Format("dd/MM/yyyy","yyyy-MM-dd hh:mm")]
    public DateTime Date{ get; set; }
}

Below I am using the CsvHelper library to parse the CSV file

 using (var streamReader = new StreamReader(filePath))
        {
            using (var csvReader = new CsvReader(streamReader, CultureInfo.InvariantCulture))
            {
                var claims = csvReader.GetRecords<Claim>().ToList();
                return claims;
            }
        }

the following is

2022-04-19 12:00:00 AM

sample CSV:

Name,Number,Date
XTC,2545454545,2022-04-19 0:00
JCF,7878421215,2022-01-20 0:00

I'm getting the following exception:

Unhandled exception. CsvHelper.TypeConversion.TypeConverterException: The conversion cannot be performed.
Text: '2022-04-19 12:00:00 AM'
MemberName: Date
MemberType: System.DateTime
TypeConverter: 'CsvHelper.TypeConversion.DateTimeConverter'

I tried the following solutions:

 var options = new TypeConverterOptions { Formats = new[] { "dd/MM/yyyy" } };
 csvReader.Context.TypeConverterOptionsCache.AddOptions<DateTime>(options);

and:

csvReader.Context.RegisterClassMap<CsvMap>()

public sealed class CsvMap : CsvHelper.Configuration.ClassMap<Claim>
    {
        public CsvMap()
        {
            const string format = "dd/MM/yyyy";
            var culture= CultureInfo.GetCultureInfo("en-US");
    
            Map(m => m.Date).TypeConverterOption.Format(format)
                .TypeConverterOption.CultureInfo(culture);
        }
    }

but I'm still getting the above exception.

How can I fix this so that I can parse the given datetime?

Answer 1

You have specified the wrong date format string:

2022-04-19 0:00
yyyy-MM-dd H:mm

or

2022-04-19 12:00:00 AM
yyyy-MM-dd h:mm:ss tt

The example you have provided and the error message do not match, so in this example I have provided mapping for both!

• h will only work for 12 hour values, so less than or equal to 12, so it will overflow for values like 14. If there is no provision for the am/pm designator (tt) ALL hour values be interpreted as am, so only use h in conjunction with tt.
• H (single H) is necessary to parse single digit hour values, but it will also match on double digit hours and correctly interpret them as 24 hour times.

Only use double hour characters (hh/HH) in scenarios where you want to force a leading zero output or when you know that the input will always have a leading zero. For parsing inputs we will always use the single hour indicator because it will work for single hour, leading zero and double digit hour inputs.

You just need to change the format expression in the FormatAttribute:

Read more about C# Custom Date and Time Format Strings

[Format("dd/MM/yyyy", "yyyy-MM-dd H:mm", "yyyy-MM-dd h:mm:ss tt")] 
public DateTime Date{ get; set; }

You can see a proof of this here: https://dotnetfiddle.net/orIGv9