Add year to Java Calendar doesn't work -

please enlight me on :

i'm trying add 10 years current date substract expiration date return number of years:

public int getmaxyears() {   int max = 0;   calendar ten_year_later = calendar.getinstance();   ten_year_later.settime(new date());   ten_year_later.add(calendar.year, 10);   calendar expiration = calendar.getinstance();   expiration.settime(expiration_date);   max = (int) (ten_year_later.gettimeinmillis() - expiration.gettimeinmillis())/(365 * 24 * 60 * 60 * 1000);   return max; } 

when debug this, calendar stay @ current year.

anyone ?

you have problem int / long conversion: 365 * 24 * 60 * 60 * 1000 evaluates 31536000000 , therefore exceeds integer.max_value 2147483647 works:

public static void main(string[] args) {           calendar ten_year_later = calendar.getinstance();           system.out.println( ten_year_later.gettime() );           ten_year_later.settime(new date());            ten_year_later.add(calendar.year, 10);           system.out.println( ten_year_later.gettime() );           calendar expiration = calendar.getinstance();            expiration.settime(expiration.gettime());            long max = (ten_year_later.gettimeinmillis() - expiration.gettimeinmillis())/(365 * 24 * 60 * 60 * 1000l);            system.out.println( "max " + max );         }