calendar-project-in-c-programm.c

#include <stdio.h>
#include <stdlib.h>

int get_1st_weekday(int year){

  int d;
  d = (((year - 1) * 365) + ((year - 1) / 4) - ((year - 1) / 100) + ((year) / 400) + 1) % 7;
  return d;
}

int main()
{
   system("Color 3F"); 

   int year,month,day,daysInMonth,weekDay=0,startingDay;

   printf("\nEnter your desired year:");
    scanf("%d",&year);

   char *months[]={"January","February","March","April","May","June","July","August","September","October","November","December"};

   int monthDay[]={31,28,31,30,31,30,31,31,30,31,30,31};

  if((year%4==0&&year%100!=0)||year%400==0)
       monthDay[1]=29;

   startingDay=get_1st_weekday(year);

   for(month=0;month<12;month++){

      daysInMonth=monthDay[month];

      printf("\n\n---------------%s-------------------\n",months[month]);

      printf("\n  Sun  Mon  Tue  Wed  Thurs  Fri  Sat\n");

      for(weekDay=0;weekDay<startingDay;weekDay++)
        printf("     ");

      for(day=1;day<=daysInMonth;day++){
        printf("%5d",day);

        if(++weekDay>6){
            printf("\n");
            weekDay=0;
        }
        startingDay = weekDay; 
      }

   }

return 0;
}