class Main {
/**
* Calculate how many days the first time is expired than second time.
* @param first
* @param second
* @return long the days
*/
public static long expireDays(long first, long second) {
if (first < second)
return 0;
long delays = first - second;
long days = delays / (1000 * 60 * 60 * 24);
return days;
}
}