// This calendar example is provided by: // http://www.codingunit.com Programming Tutorials #include #define TRUE 1 #define FALSE 0 int days_in_month[]={0,31,28,31,30,31,30,31,31,30,31,30,31}; char *months[]= { " ", "\n\n\nJanuary", "\n\n\nFebruary", "\n\n\nMarch", "\n\n\nApril", "\n\n\nMay", "\n\n\nJune", "\n\n\nJuly", "\n\n\nAugust", "\n\n\nSeptember", "\n\n\nOctober", "\n\n\nNovember", "\n\n\nDecember" }; int inputyear(void) { int year; printf("Please enter a year (example: 1999) : "); scanf("%d", &year); return year; } int determinedaycode(int year) { int daycode; int d1, d2, d3; d1 = (year - 1.)/ 4.0; d2 = (year - 1.)/ 100.; d3 = (year - 1.)/ 400.; daycode = (year + d1 - d2 + d3) %7; return daycode; } int determineleapyear(int year) { if(year% 4 == FALSE && year%100 != FALSE || year%400 == FALSE) { days_in_month[2] = 29; return TRUE; } else { days_in_month[2] = 28; return FALSE; } } void calendar(int year, int daycode) { int month, day; for ( month = 1; month <= 12; month++ ) { printf("%s", months[month]); printf("\n\nSun Mon Tue Wed Thu Fri Sat\n" ); // Correct the position for the first date for ( day = 1; day <= 1 + daycode * 5; day++ ) { printf(" "); } // Print all the dates for one month for ( day = 1; day <= days_in_month[month]; day++ ) { printf("%2d", day ); // Is day before Sat? Else start next line Sun. if ( ( day + daycode ) % 7 > 0 ) printf(" " ); else printf("\n " ); } // Set position for next month daycode = ( daycode + days_in_month[month] ) % 7; } } int main(void) { int year, daycode, leapyear; year = inputyear(); daycode = determinedaycode(year); determineleapyear(year); calendar(year, daycode); printf("\n"); }