please help with easy problem

hi guys,

This program which is no doubt extremely simple for you people is giving me some headaches. This code below tells you what day it is ,you then type a number and it tells you what day it will be in that many days.

Code:

  // what the day was yesterday

#include <iostream>
using namespace std;

int main(void)

{
	// declare variables
	const int week = 7;			// days in week
	int thatday = 0;			// the day however long ago
	int today = 4;				// today is 5th day (friday)
	int daysago = 0;
	char* weekdays[7] = {"mon","tue","wed","thur","fri","sat","sun"};
	
	do{
	// input information

	cout << endl << endl << "Today is " << weekdays[today] << endl;

	cout << "How many days forward?" << endl;

	cin >> daysago;

	

	// day was what 

	thatday = (daysago + today) % 7;			// % gets remainder




	cout  << weekdays[thatday] << endl;


	}while(daysago!=0);





	return 0;
}

What i am now trying to do is count days ago instead of days ahead.

I thought this would work

thatday = (daysago - today) % 7;

but the program crashes because of the pointer i think.

What is the best way to achieve this.

Thanks

> thatday = (daysago - today) % 7;
It does, but I think you'll find that thatday is negative

Add 7 to it?