some coding assistance please

Eaglehawk · #1 (**permalink**) 10-30-2006, 04:23 AM

i'm working to program a counter that will count when the moon is full to automate when good friday occurs, and as i was flowing through my river of thought, i encountered a dam. the method i'm taking seems simple enough to me, i've just never worked with code this way before.

in order to count the months, it was crucial to reset the days as i went through the months, i found this simple enough when i thought about it for a second for every month with 30 or 31 days. and then i crossed the elusive february.

february has an additional day every leap year, which occurs, usually, every 4 years. there are three rules that govern a leap year specifically though, as i found on google.

1. Every year divisible by 4 is a leap year.
2. a leap year is not divisible by 100
3. a leap year is not divisible by 400

what i want to do is ask the computer to divde the year by 4 to see if it is an integer, and make sure you can't divide it by 100 or 400 and get an integer. here's the function i've made so far. and yes, i know, i have two unused arrays in it so far.

PHP Code:


			
int goodfriday()
 {
      double cycledays = 29.5306;
      int month = 11;
      double day = 5;
      bool FullMoon = False;
      static double gmonth [2] = {0};
      static double gday [31] = {0};
       
       {
         Month() = month && Day() = day && Year() = 2006 && FullMoon = True;
         
         
         if (Month() == month && Day() == day + cycledays && Year == 2006)
          {
           FullMoon = True;
          }
         if ((Month() == 1 || Month() == 3 || Month() == 5 || Month() == 7 || Month() == 8 || Month() == 10 || Month() == 12) && day + cycledays > 31
         {
          month++;
          day = day + cycledays - 31;
         }
         if ((Month() == 4 || Month() == 6 || Month() == 9 || Month() == 11) && day + cycledays > 30
         {
          month++;
          day = day + cycledays - 30;
         }
         if ((Month() == 2 && Year() /*???*/) && day + cycledays > 28
         {
          month++;
          day = day + cycledays - 28;
         }
         
         
         return(0);
       }
 }

igorad · #2 (**permalink**) 10-30-2006, 08:49 AM

For definiton of duration of February in leap-year you can use
the following code:

if (Month() == 2 )
{if (MathMod(Year(),4)==0) DaysNum = 29; else DaysNum = 28;}

Eaglehawk · #3 (**permalink**) 10-30-2006, 02:04 PM

Quote:

Originally Posted by igorad

For definiton of duration of February in leap-year you can use
the following code:

if (Month() == 2 )
{if (MathMod(Year(),4)==0) DaysNum = 29; else DaysNum = 28;}

Thanks for that a ton, answers my question with division, but just out of simple curiousity, why do you campare a 4'th year to 0?

JosTheelen · #4 (**permalink**) 10-30-2006, 03:07 PM

Quote:

3. a leap year is not divisible by 400

Shouldn't this be "every year that can be divided by 400 is a leap year"?
I know that it isn't important now, but maybe over 394 years

igorad · #5 (**permalink**) 10-30-2006, 03:30 PM

Quote:

Originally Posted by Eaglehawk

Thanks for that a ton, answers my question with division, but just out of simple curiousity, why do you campare a 4'th year to 0?

Because function MathMod is:

double MathMod( double value, double value2)
The function returns the remainder of division of two numbers.
Parameters:
value - Dividend value.
value2 - Divisor value.

igorad · #6 (**permalink**) 10-30-2006, 03:37 PM

Quote:

Originally Posted by Eaglehawk

Thanks for that a ton, answers my question with division, but just out of simple curiousity, why do you campare a 4'th year to 0?

Because function MathMod is:

double MathMod( double value, double value2)
The function returns the remainder of division of two numbers.
Parameters:
value - Dividend value.
value2 - Divisor value.

If the remainder of division of two numbers is equal 0 the first are multiple to the second.

Eaglehawk · #7 (**permalink**) 10-30-2006, 11:52 PM

Quote:

Originally Posted by JosTheelen

Shouldn't this be "every year that can be divided by 400 is a leap year"?
I know that it isn't important now, but maybe over 394 years

actually, i meant what i said. according to this website, if it is divisible by 400 than it's not a leap year, here's the link, see for yourself.

http://www.timeanddate.com/date/leapyear.html

JosTheelen · #8 (**permalink**) 10-31-2006, 03:44 PM

Quote:

Originally Posted by Eaglehawk

actually, i meant what i said. according to this website, if it is divisible by 400 than it's not a leap year, here's the link, see for yourself.

http://www.timeanddate.com/date/leapyear.html

Your link also says:
This means that year 1800, 1900, 2100, 2200, 2300 and 2500 are NOT leap years, while year 2000 and 2400 are leap years.

Eaglehawk · #9 (**permalink**) 10-31-2006, 11:17 PM

Quote:

Originally Posted by JosTheelen

Your link also says:
This means that year 1800, 1900, 2100, 2200, 2300 and 2500 are NOT leap years, while year 2000 and 2400 are leap years.

right, i overlooked that, i'm not exactly an expert on leap years.

well, i may be now, lol.

thanks for saving my skin, although it may be another 393.15 years, (guessing there).