string to date conversion not working in .NET Core

Question

when i try to convert string to date following exception occured

FormatException: String '11/17/2020 3:23 PM' was not recognized as a valid DateTime.

my code is ...

public class PaperDTO
{
     ...
    [DeadLineValidate(maxday: 62, ErrorMessage = "please specify valid date maximum 62 days are valid")]
    public string DeadLine { get; set; }
    ...
}

public class DeadLineValidate : ValidationAttribute
{
    public DeadLineValidate(int maxday){ Maxday = maxday; }

    public int Maxday { get; }

    public override bool IsValid(object value)
    {
        var date = DateTime.ParseExact(value as string, "MM/dd/yyyy hh:mm tt", CultureInfo.InvariantCulture);
        return DateTime.Today <= date && date <= DateTime.Today.AddDays(Maxday);
    }
}

if i use in my action method...

Thread.CurrentThread.CurrentCulture = System.Globalization.CultureInfo.InvariantCulture;

then it works fine but in this approach i have to change culture of thread just for date conversion and unnecessarily i have to write extra code in action method of controller

does anyone have any idea regarding this ?

If your input is a string, you should also validate the string representation format. Prefer TryParseExact over ParseExact to avoid the exception — Zohar Peled
– Zohar Peled, Commented Nov 16, 2020 at 11:09
don't understand why you need to change culture of thread for this. What error will you get if you ignore this ? — Disappointed
– Disappointed, Commented Nov 16, 2020 at 11:13
Looks like you should be using h rather than hh: hh expects the hour as 2 digits i.e. 01 - 12, whereas your string is simply 3. — Johnathan Barclay
– Johnathan Barclay, Commented Nov 16, 2020 at 11:14
This error has nothing to do with ASP.NET Core or even .NET Core, in fact there are a lot of duplicate questions already. The string doesn't match the US format requested by using InvariantCulture. The fix is to not use strings in the first place. — Panagiotis Kanavos
– Panagiotis Kanavos, Commented Nov 16, 2020 at 11:18
@ZoharPeled now i am getting false my code is .. if (DateTime.TryParseExact(value as string, "MM/dd/yyyy hh:mm tt", CultureInfo.InvariantCulture, DateTimeStyles.None, out date)) — Janak Vaghasiya
– Janak Vaghasiya, Commented Nov 16, 2020 at 11:18

Peter B · Accepted Answer · 2020-11-16 11:15:31Z

2

Your date pattern requires 2 digits for the hour, but your value has only 1 digit. Try this date pattern instead, it will support both 1 and 2 digits:

"MM/dd/yyyy h:mm tt"

Note that the same issue (and the same solution) might apply for the Month and Day values.

answered Nov 16, 2020 at 11:15

Peter B

24.7k5 gold badges42 silver badges94 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

string to date conversion not working in .NET Core

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related