<PackageReference Include="System.Security.Cryptography.Pkcs" Version="11.0.0-preview.1.26104.118" />

System.Security.Cryptography.Pkcs.Pkcs9SigningTime

public sealed class Pkcs9SigningTime : Pkcs9AttributeObject
Defines the signing date and time of a signature. A Pkcs9SigningTime object can be used as an authenticated attribute of a CmsSigner object when an authenticated date and time are to accompany a digital signature.
namespace System.Security.Cryptography.Pkcs { public sealed class Pkcs9SigningTime : Pkcs9AttributeObject { public DateTime SigningTime { get; } public Pkcs9SigningTime(); public Pkcs9SigningTime(DateTime signingTime); public Pkcs9SigningTime(byte[] encodedSigningTime); } }