using System;

using System.Globalization;

​

public class Program

{

    public static void Main()

    {

        DateTime now = DateTime.UtcNow;

        CustomFormattableDateTime customNow = new CustomFormattableDateTime(now);

        string formattedDate = customNow.ToString("P", new CultureInfo("it-IT")); 

        Console.WriteLine(formattedDate);

    }

}

​

public class CustomFormattableDateTime : IFormattable

{

    private DateTime dateTime;

​

    public CustomFormattableDateTime(DateTime dateTime)

    {

        this.dateTime = dateTime;

    }

​

    public string ToString(string format, IFormatProvider formatProvider)

    {

        if (string.Equals(format, "P", StringComparison.OrdinalIgnoreCase))

        {

            // Use the custom format for the date representation (dd/MM/yyyy HH:mm:ss)

            return dateTime.ToString("dd/MM/yyyy HH:mm:ss", formatProvider);

        }

​

        // If the requested format is not "P", use the default format of the date

        return dateTime.ToString(format, formatProvider);

    }

}

​