Tracking Sheet - Drop down list with dates <= Today ( )

Hi Guys,

I'm not sure if I'm asking too much, but here goes anyway:

I'm currently in the process of creating a tracker sheet for new works, from this I want to populate fields to create a report sheet.

In my 'tracker' sheet I have the column 'Programmed Dates' which will be populated by dates as such:

H3	02/05/2014
H4	06/06/2014
H5	19/07/2014

From these dates I want to create a drop-list in my 'Report' sheet that only populates with months that were included in the 'Programmed Dates', in this instance they would be:

May-14
June-14
July-14

At present all months are populated from a pre-defined list in the 'Tracker Info' sheet but this means any new dates have to be manually added and can include dates before the current one.

I would like the drop down list to repopulate once further dates are added onto the 'Programmed Dates' sheet, e.g. 20/08/2014 (Sep-14) and 03/01/2015 (Jan-15) and so on for the foreseeable future.
Also I don't want duplicates as multiple dates can be used the same month e.g. July-14 (04/07/2014 & 28/07/2014) but I only want the one option of July-14 to be in the drop down list.

I know the following code is wrong but I've been looking along these lines:

=IF(EDATE(Tracker!D3:D19 < TODAY()), MONTH(TODAY), 2)

Any help will be much appreciated guys.

Thanks