Question

Julian day numbers (JDN) are used to provide a number for a day of the year so that calculations can be performed relatively easily to determine the difference between two dates. The JDN for a day is the number of days that have elapsed between that day and a base date of January 1, 4713 BC. Use the following calculation: JDN = (1461 × (Y + 4800 + (M − 14) / 12)) / 4 + (367 × (M − 2 − 12 × ((M − 14) / 12))) / 12 − (3 × ((Y + 4900 + (M - 14) / 12) / 100)) / 4 + D – 32075 Once the above is calculated, input two dates, convert them to their JDNs, and take the difference of the JDNs. Write a C# program to find the difference between two dates using the method above. Error check dates- where day is an integer from 1 to 31, month goes from 1 to 12, and year goes from 1600 to 2100. Finally, ask the user to run the program again. A user-defined function must be used with the calculation. Do not use the C# DateTime object in this problem. Refer to the sample output below. Sample Run: Enter the first date (MM/DD/YYYY): 9 7 1980 Enter the second date (MM/DD/YYYY): 6 11 2012 Days between dates 09/07/1980 and 06/11/2012 is: 11600 Run Again (Y/N)? n

Answer 1

using System;
                  
public class Program
{
   public static void Main()
   {
           String runAgainFlag;
           do{
           // reads first date
Console.Write("Enter the first date (MM/DD/YYYY): ");
           String firstDateString;
           firstDateString = Console.ReadLine();
           // convert date into Julian Date Number using user defined method getJulinaDateNumber(String dateString)
           int jdnOfFirstDate = getJulianDateNumber(firstDateString);
  
           // reads second date
           Console.Write("Enter the second date (MM/DD/YYYY): ");
           String secondDateString;
           secondDateString = Console.ReadLine();
           // convert date into Julian Date Number using user defined method getJulinaDateNumber(String dateString)
           int jdnOfSecondDate = getJulianDateNumber(secondDateString);
  
           // print difference between the two dates
           int dateDifference;
           if(jdnOfSecondDate > jdnOfFirstDate){
               dateDifference = jdnOfSecondDate - jdnOfFirstDate;
           }else
               dateDifference = jdnOfFirstDate - jdnOfSecondDate;
              
           // print difference between the dates entered
Console.Write("Days between dates " + firstDateString + " and " + secondDateString + " is: " + dateDifference);
          
           Console.Write("Run Again (Y/N)");
runAgainFlag = Console.ReadLine();
       }while(runAgainFlag.Contains("Y") || runAgainFlag.Contains("y"));
   }
   public static int getJulianDateNumber(String dateString){
       String[] dateAttributes = new String[3];
      
       //split the date into months, days and years based on / or space
       //If date does not contains / or space then it can't be splitted and the variable dateAttributes remains empty
           if(dateString.Contains("/")){
               dateAttributes = dateString.Split('/');
           }else if (dateString.Contains(" ")){
               dateAttributes = dateString.Split(' ');
           }
           if(dateAttributes.Length != 3){
               Console.Write("Date is not in proper format");
               System.Environment.Exit(0);
           }
           int M = 0;
           int D = 0;
           int Y = 0;
      
       //If dateAttributes is empty the program throws IndexOutOfRangeException which is handled using try catch
       //In the catch block program prints a string and stops the execution
       try{
           M = int.Parse(dateAttributes[0]);
           D = int.Parse(dateAttributes[1]);
           Y = int.Parse(dateAttributes[2]);
       }catch(Exception){
           Console.Write("Date is not in proper format");
           System.Environment.Exit(0);
       }
      
       //check if all the variables month,day and year are in range specified using user defined method checkForRange(int value, int lowerLimit, int upperLimit)
       if(checkForRange(M,1,12) == false){
           Console.Write("Month should be in range 1 and 12");
           System.Environment.Exit(0);
       }
       if(checkForRange(D,1,31) == false){
           Console.Write("Day should be in range 1 and 31");
           System.Environment.Exit(0);
       }
       if(checkForRange(Y,1600,2100) == false){
           Console.Write("Year should be in range 1600 and 2100");
           System.Environment.Exit(0);
       }
      
       //formula to convert date into Julian date number is written directly in return statement
       //The formula is calculated and returned to the point where getJulianDateNumber is being called
       return (1461 * (Y + 4800 + (M - 14) / 12))/4 + (367 * (M - 2 - 12 * ((M - 14) / 12))) / 12 - (3 * ((Y + 4900 + (M - 14) / 12) / 100)) / 4 + D - 32075;
   }
  
   public static bool checkForRange(int value, int lowerLimit, int upperLimit){
       if(value >= lowerLimit && value <= upperLimit){
           return true;
       }else
           return false;
   }
  
   /*
   * The method getJulianDateNumber(String dateString) takes date string in the format MM/DD/YYYY or MM DD YYYY and converts the date string into Julian day number
   * If the string is not in the format MM/DD/YYYY or MM DD YYYY, the program prints an error and stops execution
   * The variables M,D and Y denote month, day and year respectively
   * If month is not in range 1 and 12, the program prints an error and stops execution
   * If day is not in range 1 and 31, the program prints an error and stops execution
   * If year is not in range 1600 and 2100, the program prints an error and stops execution
   */
  
   /*
   * The method checkForRange(int value, int lowerLimit, int upperLimit) checks if value is in range between lowerLimit and upperLimit
   * If the value is in range the method returns true or else it returns false
   */
}