No. That's incorrect. That would cause the year to go up on Dec. 31st (day 366), turning it into day 0. In fact, what you want is to change the while to an if s

No. That's incorrect. That would cause the year to go up on Dec. 31st (day 366), turning it into day 0. In fact, what you want is to change the while to an if statement. If it really does need to run as a while statement (to add more than one year at once?), then the alternative would be a break statement after line 271.