Data

public class MyClass{
  main(){
//Date - Time Class
    Data date = new Date();
// Format : DateFormat-> SimpleDateFormat
    String format = "yyyy年MM月dd日  HH:mm:ss tt";
//d  dd  E  M  y  yy
    SimpleDateFormat dataformat = new SimpleDateFormat(format);
String str = dataFormat.format(date);
System.out.out.println(str);
//2020年04月02日  17:52:10
  }
}

Calender (Abstract class)

public class MyClass{
main(){
    Calender calender = Calender.getInstance();
// Get the calender- calender.get(Calender.YEAR)
//calender.get(Calender.MONTH)
//calender.get(Calender.DATE)
//calender.get(Calender.HOUR)
//calender.get(Calender.MINUTE)
//calender.get(Calender.SECOND)
System.out,println(calender.get(Calender.YEAR));

  }
}