if I'm using a class within another class

For example I have a class called Date that holds a day+month+year, and I wanna use it in my trip class constructor in such a way

public Trip (String guideName, Date depDate, Date retDate, int noOfCountries, int noOfTravellers)


Is it enough to just have Date.java and Trip.java in the same folder or am I supposed to import something?


Also a bit harder question: how would you go about calculation how many saturdays are within a certain trip? (departure date until return date)