Values Repeating with INDEX

[gem333]

I am working on a very large file for my office and have run into a roadblock. We need to pull unique invoice numbers from a large export that is copied into the workbook based on the corresponding dates. I have gotten it to a point where it will pull the unique dates within the range I give it and fill in the corresponding invoice numbers, but once we hit the third invoice on a duplicate date, it will fill in the first unique invoice number. 

EXAMPLE DATA (& HOW IT NEEDS TO LOOK):	HOW IT PULLS INTO SHEET:
Day 1 - 10001	Day 1 - 10001
Day 1 - 10002	Day 1 - 10002
Day 1 - 10003	Day 1 - 10001
Day 1 - 10004	Day 1 - 10002

Here is a link to a neutral version of the workbook for anyone who is willing to attempt to help!

Audit Help Workbook

Thank you in advance!

[#2]

@gem333 

My first choice would be a formula-free solution: Pivot table with timeline.

[#3 · Accepted solution]

@gem333 

Use the same formula you used for column A, but change the array to 'ORIG EXP'!D7:D1000.

=FILTER('ORIG EXP'!D7:D1000,('ORIG EXP'!A7:A1000>=MAIN!K3)*('ORIG EXP'!A7:A1000<=MAIN!K4),"NO RESULTS")

[#4]

@Rsartori76 that worked! Thank you for the simple fix.