indexing - Excel: Index Match using criteria, show unique values? -

i trying create calendar in excel. have sheet 1 contains calendar template so:

april 8           april 9           april 10           april 11         april 12  subjecta          subjectd          subjectg           subjectj         subjectk descriptiona      decriptiond       descriptiong       descriptionj     desc k   subjectb          subjecte          subjecth          descriptionb      descriptione      descriptionh   subjectc          subjectf          subjecti descriptionc      descriptionf      descriptioni 

i have rows of data in sheet 2 so:

id      date            subject      description 1       08/04/2016      subjecta     descrptiona 2       08/04/2016      subjectb     descriptionb 3       08/04/2016      subjectc     descriptionc 4       09/04/2016      subjectd     descriptiond 5       09/04/2016      subjecte     descriptione 6       09/04/2016      subjectf     descriptionf 7       10/04/2016      subjectg     descriptiong 8       10/04/2016      subjecth     descriptionh 9       10/04/2016      subjecti     descriptioni 10      11/04/2016      subjectj     descriptionj 11      12/04/2016      subjectk     desc k 

basically want use index match formula in cells of calendar give me 'subjects' dates match.

for instance on sheet 2 there 3 rows subjects 'a','b', , 'c' date 08th april. therefore these should show in calendar on sheet 1 under 08th april.

i trying use formula this:

=index(data!$g$2:$g$5000, match(0, countif(calendar!$g$18:$g18, data!$g$2:$g$5000), 0)) 

this should pull through subjects have matching date , display unique values. it's not working, pulls through result without ensuring dates match, , doesn't show unique values shows same value again , again.

i think need define date match in formula somewhere not sure how, or where?

please can show me going wrong?

thanks in advance

to multiple solutions need array formula row rows index small (assuming dates in column b , subjects in d)

=index(data!$d:$d,small(if(data!$b$2:$b$5000=calendar!$g$18,row($2:$5000)),xxx)) 

this array formula , needs confirmed ctrl + shift + enter

simply change xxx 1 first match, 2 second , on.
if still have questions ask ;)

(done phone, may contain errors)