Java, How to subtract Date objects whilst considering DST -

i have piece of code used calculate number of days between 2 date objects, , in instances, works fine. however, if date range between 2 objects includes end of march, result 1 less should be. e.g march 31 2014 - march 29 2014 = 1, whereas should 2.

i understand due fact march has 30 days of 24 hours , 1 day of 23 hours due dst, cause of value being 1 less.

however, not sure best way account missing hour.

   // have     int numdays = (int) ((dateto.gettime() - datefrom.gettime()) / (1000 * 60 * 60 * 24));     // have tried rounding, since should have 23 hours left over, didn't work.     int numdays = (math.round(dateto.gettime() - datefrom.gettime()) / (1000 * 60 * 60 * 24)); 

any help/pointers appreciated.

i , have use java 7 , not able use jodatime unfortunately.

your second example close. parentheses math.round() surround subtraction, though, since that's integer (well, long really), nothing happens, , divide. other problem second bit of code doing integer division truncates part after decimal point. try this:

long numdays2 = math.round((dateto.gettime() - datefrom.gettime()) / (1000.0 * 60 * 60 * 24)); 

(as indicated, changed math.round() parens, , made floating point division making divisor double.)

as indicated comments, though, hack. in particular, tell there 2 days between 6am march 5 , 8pm march 6. it's not want. try on size instead:

    simpledateformat fmt = new simpledateformat("yyyy-mm-dd");     calendar cal = calendar.getinstance();     cal.settime(fmt.parse("2014-03-29"));     long start = cal.gettimeinmillis();     start += cal.gettimezone().getoffset(start);     cal.settime(fmt.parse("2014-03-31"));     long end = cal.gettimeinmillis();     end += cal.gettimezone().getoffset(end);      system.out.println((end - start)/86400000.0); 

is ugly? yes. weird? yes. work? yes (i think so). note i'm providing double result; can apply rounding want result.