1014 Holmes appointments, C

#include <stdio.h>
int main()
{
	int i=0,j=0,DAY=0,hour,minute;
	char a[60] = {0};
	char b[60] = {0};
	char c[60] = {0};
	char d[60] = {0};

	scanf("%s %s %s %s",a,b,c,d);

	while(a[i] && b[i])
	{
		if( a[i]>64 && a[i]<91 && b[i]>64 && b[i]<91 && a[i] == b[i] && j==0)
		{DAY = a[i]-64; j=1;}
	
		else if(a[i]>47 && a[i]<58 && b[i]>47 && b[i]<58 && a[i] == b[i] && j==1)
		{hour = a[i]-48; j++;}
		else if(a[i]>64 && a[i]<79 && b[i]>64 && b[i]<79 && a[i] == b[i] && j==1)
		{hour = a[i]-55; j++;}
		
		i++;
	}
	i = 0; j = 0;
	while(c[i] && d[i])
	{
		if( c[i]>96 && c[i]<123 && d[i]>96 && d[i]<123 && c[i] == d[i] && j==0)
		{minute = i; j++;}
		
		i++;
	}

	switch(DAY%7)
	{
	case 1:printf("MON %02d:%02d",hour,minute);	break;
	case 2:printf("TUE %02d:%02d",hour,minute);	break;
	case 3:printf("WED %02d:%02d",hour,minute);	break;
	case 4:printf("THU %02d:%02d",hour,minute);	break;
	case 5:printf("FRI %02d:%02d",hour,minute);	break;
	case 6:printf("SAT %02d:%02d",hour,minute);	break;
	case 0:printf("SUN %02d:%02d",hour,minute);	break;
	}
	

    return 0;
}