Thread: Help with Clock (advance and reverse day,hour,minute)

FYI - This is my first post. This is an assignment for a JAVA I class. I cannot import anything or change the public class. My problem right now focusing on the ADVANCE method, I don't know how to advance the day. So my question is how should I get a if/then, for, or while component in there to anchor my advancing minutes to my days?

public class ClockDriver {
 
    public static void main(String[] args) {
        Clock MyClock = new Clock("Thursday", 12,0); // Instantiate a clock object
 
	System.out.println(MyClock); // Should display: Thursday, 12:00 p.m.
        System.out.println(); // print blank line
 
        MyClock.advance(150); // advance time 150 minutes (2 hours 30 minutes)
	System.out.println(MyClock); // Should display: Thursday, 2:30 p.m.
        System.out.println();
 
        MyClock.advance(585); // advance time by 585 minutes (9 hours 45 minutes)
	System.out.println(MyClock); // Should display: Friday, 12:15 a.m.
        System.out.println();
 
        MyClock.advance(10080); // advance time by 10080 minutes (7 days)
	System.out.println(MyClock); // Should display: Friday, 12:15 a.m.
        System.out.println();
 
        MyClock.reverse(585); // reverse time by 585 minutes (9 hours 45 minutes)
	System.out.println(MyClock); // Should display: Thursday, 2:30 p.m.
        System.out.println();
 
        MyClock.reverse(17280); // reverse time by 17280 minutes (12 days)
	System.out.println(MyClock); // Should display: Saturday, 2:30 p.m.
        System.out.println(); 
    } // end of main
 
} // end of class ClockDriver
 
class Clock{
    /***************************************************************
     * Objects of this class represent time (in hours and minutes) *
     * The time data is stored in 24 hour (HHMM military format)   *
     ***************************************************************/
    private int day_of_week; // valid range of values is 1 thru' 7
    private int hours; // range of values is 0 thru' 23
    private int minutes; // range of values is 0 thru' 59
    private String[] dow = {"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"};
 
    public Clock(String s, int h, int m){
       //Initialize day_of_week, hours and minutes  - 20 points
        if (s.equals("Sunday")) {
            day_of_week = 1; 
        }
        else if (s.equals("Monday")) {
            day_of_week = 2;
        }
        else if (s.equals("Tuesday")) {
            day_of_week = 3;
        }
        else if (s.equals("Wednesday")) {
            day_of_week = 4;  
        }
        else if (s.equals("Thursday")) {
            day_of_week = 5;
        }
        else if (s.equals("Friday")) {
            day_of_week = 6;
        }
        else if (s.equals("Saturday")) {
            day_of_week = 7;    
        } else { 
            day_of_week = -1;
                    }
        hours = h;
        minutes = m;
 
    }
 
    public void advance(int m){
        // advance day_of_week, hours and minutes - 30 points
 
        int allMinA = (hours * 60) + minutes + m;
        minutes = allMinA % 60;
        hours = (allMinA / 60) % 24;
    }
 
    public void reverse(int m){
	// reverse day_of_week, hours and minutes - 30 points   
 
        int allMinB = (hours * 60) + minutes - m;
        minutes = allMinB % 60;
        hours = (allMinB / 60) % 24;
    }
 
    public String toString(){
	//return Day of the week, hours and minutes as a string to be displayed - 20 points
 
        if (hours >12){
            hours = hours - 12;
        }
        String result = dow[day_of_week - 1] + ", " + String.format("%2d", hours) + ":" + String.format("%02d", minutes) + " amORpm > ";
 
        return result;
    }
} // end of class Clock

I can visualize a set of total minutes that I can divide by to find out how many days, hours, and minutes but... the way these methods are set up I am having a hard time getting total minutes. Because hours needs to be set to zero after the first advance otherwise it adds unnecessarily to totalMinutes. So below I have a new approach. Once again any suggestions would be appreciated.

 public void advance(int m){
        // advance day_of_week, hours and minutes - 30 points
 
        minutes = minutes + m;
        if (minutes < 60){
 
        } else {
 
            hours = hours + (minutes / 60);
            minutes = minutes % 60;
 
            if (hours < 24){
            } else {
                int addDays = day_of_week + (hours / 24);
                if (addDays < 8){
                    day_of_week = addDays;
                } else {
                    int weekAdds = addDays - 8;
                    day_of_week = weekAdds;
 
                }
 
            }
        }
 
    }

No, the code in my previous post doesn't work. I can't keep track of the days in any consistent fashion with that approach. My problem is I don't understand the best approach to keep track of time in this program. I need a counter that knows the starting point and can keep track of minutes (0-59) and hours (0-23) and days (1-7). I think I am now going to stop keeping track of total minutes and try to keep track of total hours. Hours are what I need to know when I need to add ++ to days.
----------
For example, if I start at Thursday at 12:00pm and time advances by 10 days (240 hrs or 14,400 mins) then the clock would stay at 12:00pm but the day should be Sunday. If Sun = 1, Mon = 2, .... Sat = 7, then I have (Thursday) 5 + 10 (days) = 15. But how does that 15 help me?

I'm much happier with this method for keeping track of the correct hours but I am still having issues keeping track of days. Any help out there? Kevin? Anyone! lol

 public void advance(int m){
        // advance day_of_week, hours and minutes - 30 points
 
        minutes = minutes + m;
 
 
        if(minutes > 59){
            int spillOverMins = minutes % 60;
            int spillOverHours = minutes / 60;
            hours = hours + spillOverHours;
            minutes = spillOverMins;
        } else {
          // not sure if I need something here
        }
 
        if (hours > 23){
            int spillOverHours2 = hours % 24;
            int spillOverDays = hours / 24;
            hours = hours + spillOverHours2;
 
          if(spillOverDays + day_of_week > 7){
 
                // what to put here that will account for the original day_of_week
          } else {
 
              day_of_week = day_of_week + spillOverDays;
 
          }  
        }
 
    }

Have you considered the % operator?

Chris

The advance method works:

public void advance(int m){
        // advance day_of_week, hours and minutes - 30 points
 
        minutes = minutes + m;
 
          if(minutes > 59){
            int spillOverMins = minutes % 60;
            int spillOverHours = minutes / 60;
 
            hours += spillOverHours;
            minutes = spillOverMins;
        } // END if(minutes > 59){
 
        if (hours > 23){
            int spillOverHours2 = hours % 24;
            int spillOverDays = hours / 24;
 
            hours = spillOverHours2;
            day_of_week += spillOverDays;
        } // END if (hours > 23){
 
 
        if (day_of_week > 7) {
            day_of_week = day_of_week%7;
            if (day_of_week == 0) day_of_week = 7;
        }// END if (day_of_week > 7) {
 
    } // END advance()

but the reverse is not as easy to figure out. What is best way to get keep of time going backwards, in this case?

 public void reverse(int m){
	// reverse day_of_week, hours and minutes - 30 points   
 
         int backMins = m % 60;
         int backHrs = m / 60;
         int backDays = backHrs / 24;
 
         int addBackHr = 0;
         int addBackDay = 0;
 
          int minCheck = minutes - backMins;
          if (minCheck < 0) {
              addBackHr = 1;
              minutes = minCheck * -1;
 
          } else {
              minutes = minCheck;
          } // END   if (minCheck < 0) {
 
          int hrCheck = hours - (backHrs + addBackHr);
 
      if (hrCheck < 0) {
 
          hrCheck *= -1;
 
      if (hrCheck > 24) hrCheck = (backHrs + addBackHr) % 24;
      if (hours == 0) hours = 24;
      hours = hours - hrCheck;
      } else {
          hours = hours - hrCheck;
      }// END  if (tmpHoldHrs < 0) {
 
      day_of_week -= (backDays + addBackDay);
 
       if(day_of_week == 0) day_of_week = 1;
      if (day_of_week < 0){
 
 
       day_of_week *= -1;
       if(day_of_week > 7) day_of_week = day_of_week % 7;
 
      }
 
    } // END reverse()