Calculating Days

[francis varkey]

Respected Sirs,

What is the best way for calculating number of days between two dates(java.util.Date object) ?

Thanks
Francis

[Rob Spoor]

Use java.util.Calendar:

Calendar cal1 = Calendar.getInstance();
cal1.setTime(date1);
Calendar cal2 = Calendar.getInstance();
cal2.setTime(date2);
 
int day1 = cal1.get(Calendar.DAY_OF_YEAR);
int day2 = cal2.get(Calendar.DAY_OF_YEAR);
int diff = day2 - day1;
 
// check for different year
int year1 = cal1.get(Calendar.YEAR);
int year2 = cal2.get(Calendar.YEAR);
while (year1 < year2)
{
    diff += cal1.getActualMaximum(Calendar.DAY_OF_YEAR);
    cal1.add(Calendar.YEAR, 1);
}
while (year1 > year2)
{
    cal2.add(Calendar.YEAR, 1);
    diff -= cal2.getActualMaximum(Calendar.DAY_OF_YEAR);
}
return diff;

[francis varkey]

Wrong code:
please provide inputs "04/06/2008" and "05/09/2008".

[Rob Spoor]

Which produces 93, just like Visual Basic's DateDiff function does.
Well, that, is, using dd/MM/yyyy as the format. Otherwise it's 33, just like Visual Basic's DateDiff function does