Hello forum!

I am new here. I am very passionate about excel, and for that my boss assigned me a task to perform. This task is about to create a template, but now I am stuck because I have to use a matrix formula and I dont know how to use them properly. I will explain the procces very quickly, but my doubt is very specific.

Template 1 (for user) - DONE
Item Start date Finish date Status
1 01/06/18 04/06/18 Check
2 10/06/18 14/06/18 OK
1 01/06/18 04/06/18 OK
3 08/06/18 12/06/18 Check

Template 2 (database per day) - DONE
Item Date Status
1 01/06/18 Check
1 02/06/18 Check
1 03/06/18 Check
1 04/06/18 Check
2 10/06/18 Ok
2 11/06/18 OK
2 12/ 06/18 OK
2 13/06/18 OK
2 14/06/18 OK
1 01/06/18 OK
1 02/06/18 OK
1 03/06/18 OK
1 04/06/18 OK
3 08/06/18 Check
3 09/08/18 Check
.........so on.........
3 12/06/18 Check

This sheet is automatic from the template before. I think it is the best option to organize the data in order to analyze after because there are a lot of items. In this sheet, i am not totally sure if it is better to keep a history of each item when the status is “check” and then repeat it when turn into “Ok” or just update it when the user enter the record in the first template. Every suggestion is welcome.

Template 3 (database of days missing per item) - NOT DONE

Here I have to create a table like the above but with the missing date per item. I think I will have to use a matrix function but I am not sure about it. The table will be like this:

Start date: 01/06/18
Reference date: 30/06/18 (normally it will be today function)

Item Date
1 05/06/18
1 06/06/18
.....
1 30/06/18
2 01/06/18
2 02/06/18
.....
2 09/06/18
2 15/06/18
2 16/06/18
....
2 30/06/18
3 01/06/18
3 02/06/18
3 03/06/18
....
3 07/06/18
3 13/06/18
...
3 30/06/18

Sorry if the message it is too long, i just wanted to explain the whole proccess, but my doubt it is mostly about the last template. I could do the template 2 without using matrix formulas but here i am not able to do it. Also, if you need to know there is a sheet with all the items listed with an ID (over 300).

So, if you can help me i will really appreciate it.
Thank very much.

Ps: sorry for the format of the message but i am in the phone now, if you need a file to understand the problem better I can upload it tomorrow.