using System;

using System.Linq;

public class Program

{

    public static void Main()

    {

        DateTime TodayDate =  new DateTime(2023,02,28);     

        DateTime ExpiryDate =  new DateTime(2023,05,30);

​

        var CalculatedDate = TodayDate.AddMonths(3);        

        var CalculatedReverseDate = ExpiryDate.AddMonths(-3);

​

        Console.WriteLine("TodayDate  "+ TodayDate);        

        Console.WriteLine("ExpiryDate  "+ ExpiryDate);      

        Console.WriteLine("CalculatedDate  "+ CalculatedDate);      

        Console.WriteLine("CalculatedReverseDate  "+ CalculatedReverseDate);

    }

}