Date Function - How can I get the six month previous and 6 month next date from a date.

[vishalrajpoot3]

Please help me to get the 6 month next date and previous date from the below dates.  Also suggest me where I am mistaking?

Set-A Migration_Date

1-Oct-10

1-Jun-10

1-Apr-11

1-Oct-10

1-Nov-10

1-Jun-10

1-Oct-10

1-Jan-14

1-Mar-11

data date_treat;
set A;
sixmonth_backdt=intnx('month','Migration_dt'd,-6,'B');
format sixmonth_backdt date9.;
run;

[PeterClemmensen]

data Set_A;
input Migration_Date:date7.;
format Migration_Date date7.;
datalines;
1-Oct-10
1-Jun-10
1-Apr-11
1-Oct-10
1-Nov-10
1-Jun-10
1-Oct-10
1-Jan-14
1-Mar-11
;

data want;
   set Set_A;

   /* Exactly six months back */
   sixmonth_backdt=intnx('month',Migration_Date,-6,'S');

   /* Six months back, start of month */
   sixmonth_backdt_b=intnx('month',Migration_Date,-6,'B');

   /* The day before */
   The_Day_Before=Migration_Date-1;

   format _numeric_ date7.;

run;