# C > Beginners Lab Assignments Code Examples

## Program to compute difference between two dates

``` Program to compute difference between two dates #include<stdio.h> #include<math.h> void main() { int day1,mon1,year1,day2,mon2,year2; int ref,dd1,dd2,i; clrscr(); printf("Enter first day, month, year"); scanf("%d%d%d",&day1,&mon1,&year1); scanf("%d%d%d",&day2,&mon2,&year2); ref = year1; if(year2<year1) ref = year2; dd1=0; dd1=func1(mon1); for(i=ref;i<year1;i++) { if(i%4==0) dd1+=1; } dd1=dd1+day1+(year1-ref)*365; printf("No. of days of first date fronm the Jan 1 %d= %d",year1,dd1); /* Count for additional days due to leap years*/ dd2=0; for(i=ref;i<year2;i++) { if(i%4==0) dd2+=1; } dd2=func1(mon2)+dd2+day2+((year2-ref)*365); printf("No. of days from the reference year's first Jan = %d",dd2); printf("Therefore, diff between the two dates is %d",abs(dd2-dd1)); getch(); } int func1(x) //x for month y for dd { int y=0; switch(x) { case 1: y=0; break; case 2: y=31; break; case 3: y=59; break; case 4: y=90; break; case 5: y=120;break; case 6: y=151; break; case 7: y=181; break; case 8: y=212; break; case 9: y=243; break; case 10:y=273; break; case 11:y=304; break; case 12:y=334; break; default: printf("Error encountered"); exit(1); } return(y); } ```