X509Certificate.GetExpirationDateString Method ()


Returns the expiration date of this X.509v3 certificate.

Namespace:   System.Security.Cryptography.X509Certificates
Assembly:  mscorlib (in mscorlib.dll)

public virtual string GetExpirationDateString()

Return Value

Type: System.String

The expiration date for this X.509 certificate.

The expiration date is the date after which the X.509 certificate is no longer considered valid.

The GetExpirationDateString method returns a string that shows the date formatted in Short Date Pattern followed by the time formatted in Long Time Pattern. The date and time are formatted using the current culture and time zone.


This method may return a different string format on Macintosh computers, although the underlying DateTime object will represent the same value.

The following example uses the GetExpirationDateString method to get the expiration date of a certificate and displays it to the console.

using System;
using System.Security.Cryptography.X509Certificates;

public class X509

    public static void Main()

        // The path to the certificate.
        string Certificate =  "Certificate.cer";

        // Load the certificate into an X509Certificate object.
        X509Certificate cert = X509Certificate.CreateFromCertFile(Certificate);

        // Get the value.
        string results = cert.GetExpirationDateString();

        // Display the value to the console.



.NET Framework
Available since 1.1
Available since 2.0
Windows Phone Silverlight
Available since 7.0
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