Every few days between 5169. Date

class Solution {
public:
    void CutString(string &s) {
        for (int i = 0; i < s.size(); i++) {
            if (s[i] == '-') {
                s.erase(s.begin() + i);
            }
        }
    }
    int daysBetweenDates(string date1, string date2) {
        CutString(date1);
        CutString(date2);
        tm inf1 = { 0 };
        tm inf2 = { 0 };
        int first, second;
        stringstream s1, s2;
        
        s1 << date1;
        s1 >> first;
        
        s2 << date2;
        s2 >> second;

        inf1.tm_year = (first/10000) - 1900;
        inf2.tm_year = second/10000 - 1900;
        
        inf1.tm_mon = ((first / 100) % 100) - 1;
        inf2.tm_mon = ((second / 100) % 100) - 1;
        
        inf1.tm_mday = first % 100;
        inf2.tm_mday = second % 100;
        
        time_t one = mktime(&inf1);
        time_t two = mktime(&inf2);
        
        return abs(difftime(one, two) /60/60/24);
    }
};