java - Creating a DateTime from two other dates -

basically want see if someones birthday within 3 months of todays date. going use days , "90" days.
thoughts follows:

• i set new datetime todays date , grab dob of person in question.
• i want take day , month dob , year todays date.
• then these days, months , years merged 1 new date.

for example:

dob 04/05/1987
today 10/05/2013
newbirth 04/05/2013

how can achieve part grab days/months 1 date, years another, , put these 1 date?

(only key factors, im aware rule wouldn't run)

import org.joda.time.readableinstant; import org.joda.time.datetime; import org.joda.time.days; import org.joda.time.months; import org.joda.time.years;  rule"blah" salience 1 when proposer($dob : dateofbirth) datetime newbirth = new datetime() datetime today = new datetime(); #grab dob day , month #grab todays year #turn "newbirth" combination of above 2 lines int $birthday = (days.daysbetween((readableinstant)today,(readableinstant)newbirth).getdays()); if ($birthday <= 90){ logger.info("hurrraaayyyyyy"); } end 

i standard jdk calendar

boolean iswithin3month(int y, int m, int d) {     calendar = calendar.getinstance();     calendar birthday = new gregoriancalendar(y, m, d);     int currentmonth = now.get(calendar.month);     int birthdaymonth = birthday.get(calendar.month);     int monthdiff;     if (birthdaymonth < currentmonth) { // eg birth = jan (0) , curr = dec (11)          monthdiff = 12 - currentmonth +  birthdaymonth;     } else {         monthdiff = birthdaymonth - currentmonth;     }     if (monthdiff < 0 || monthdiff > 3) {         return false;     } else if (monthdiff == 0) {         return birthday.get(calendar.date) >= now.get(calendar.date);     }     return true; }