int currentTimeHr = tm->hour;
int currentTimeMin = tm->min;

int endTimeHr = currentTimeHr + 12;
int endTimeMin = currentTimeMin;

int nextIntervalHour = currentTimeHr
int nextIntervalMin = currentTimeMin + n; //n is interval
if(nextInvervalMin >= 60) {
    nextIntervalHour++;
    nextIntervalMin -= 60;


while(currentTimeHr and currentTimeMin != endTimeHr and endTimeMin) {
    //Get new current time and assign it to the variables. Not gonna write this out.
    //When a variable has time from now on, i'm shortening it but I mean to check both the hour AND the minutes.
    if(currentTime == nextIntervalTime) {
        cout << "Good whatever" << endl;
        //Update the interval time to the next interval like I did previously up there ^^^^
    }