using System;

public class Program

{

    public static void Main()

    {

        var date1 = DateTime.Parse("12/31/2021 06:40:00"); //DateTimePicker1 

        var date2 = DateTime.Parse("01/08/2022 06:40:00"); //DateTimePicker2

​

        var days = (date1-date2).TotalDays;

        var days2 = (date1 - date2).ToString(@"dd\d\ hh\h\ mm\m\ ");

        Console.WriteLine(days);

        Console.WriteLine(days2);

​

​

    }

}