List missing dates across 2 tabs

[virtuosok]

Hi,
I have the following array formula to calculate the # of unique dates (excluding duplicates and blanks) in line with one pre-defined criterion, across two tabs
=SUM(IF(FREQUENCY(IF('Tab One'!$E$13:$E$50000=C4,'Tab One'!$F$13:$F$50000),ROW(INDIRECT("1:60000")))+FREQUENCY(IF('Tab Two'!$E$13:$E$50000=C4,'Tab Two'!$F$13:$F$50000),ROW(INDIRECT("1:60000"))),1))

Is there a way to list these unique entries in a single cell rather than just do SUM? Or, much better, is there a way to pull a list of missing entries? Ideally in a single cell, but a column on a separate sheet will also do.
Thanks

 

[virtuosok]

Or let me put it this way.
Let's assume we have Tab One with names in column A, and dozens of dates against each name in column B. Some duplicates, some unique.
The same names and a comparable, but not identical, date range on Tab Two (same columns).
Now Tab Three would have all names listed once in each row, with their start date and end date as it goes below. I need to figure out a formula for column D which will pull all missing dates from two previous tab, as long as they are in B1-C1 range, for each person.

A1 (name)​	B1 (start date)​	C1 (end date)​	D1 Missing dates​
John	01 Jan 10	31 Dec 10
Jack	01 Jan 15	31 Aug 17
Jay	01 Jan 20	31 May 20

Or, have the output this way:

Name​	John​	Jack​	Jay​
Missing dates in range	02 Jan 10	etc	etc
	15 Feb 10	etc	etc
	25 Apr 10	etc	etc
	30 Apr 10	etc	etc

Any ideas appreciated....

 

[virtuosok]

Let me copy the link to the actual workbook (blinded) in hopes that this might help finding a solution.
Please check the formula on tab 3, column M. Is there any way to pull the list of actual unique days rather than their SUM? Or, better still, is there a way to pull the list of missing dates, for each subject in column C? (i.e. dates missing between their "first date" and "last date", columns G and J, correspondingly)
My Excel version unfortunately doesn't support TEXTJOIN, so I'm guessing it's either a CONCAT+TRANSPOSE (which is very manual and probably won't work), or maybe VBA?
Workbook