Yes please. Other than googling and asking online, I tend to like looking at what/how it's done and break it down to understand the elements. All training with be much appreciated if you can explain the formula breakdown.

I can obviously see the elements in Excel as it shows range, criteria etc. Gets well complex with a lot of nested formulas as well.

Ok, I will try to explain it the best I can

Formula - =COUNTIFS($A:$A,"<="&TODAY(),$A:$A,">"&TODAY()-365,B:B,"A")

The COUNTIFS allows you to build up a number of conditions to pull back results and is built up with however many criteria you want, but the more you add, the more complicated it can get, so the one above is fairly simple relatively speaking as it only has 3 criteria to check

**Criteria 1 - $A:$A,"<="&TODAY()**
Using your sheet with the dates in column A and then staff in columns B to ... (however many staff you have)

The first part of the criteria is saying use column A (the entire column, not a specific number of rows) and is locked to prevent it changing if you copy the formula to another column

The second part of the criteria is checking to see if the date in the cell in column A is today or a date prior to today (this is how you can use rolling date periods)

You need to use double quotes when using parameters such as those used in this formula and then use '&' to add on the wording - if you were to use the TODAY function as part of the formula in a cell it would simply be <=TODAY() without the quotes

**Criteria 2 - $A:$A,">"&TODAY()-365**
This is pretty much the same as the first part of the formula, but is instead looking for a date that is between today and 365 days ago (again, how you can use a rolling date period)

**Criteria 3 - B:B,"A"**
This final bit of the formula is looking in the column of the staff member (in this case, the staff member in column B) and looking for where there is a value of 'A' in the cell (this could be changed to whatever letter or word you want)

As this reference of column B is not locked, when you copy this formula to column C / D / E / etc, that part of the formula will change to reflect the column it is copied to, but the locked references earlier in the formula will still reference column A

So if you copied the formula to column C for the next staff member, it would look like this -

=COUNTIFS($A:$A,"<="&TODAY(),$A:$A,">"&TODAY()-365,

**C:C**,"A") and so on

When combining all elements of the formula, it is counting up all instances in the staff column where the date falls between today AND 365 days ago AND where the cell value is equal to 'A'

If you kept this sheet with only the dates and staff columns on it, by using the TODAY() function you can just keep adding dates to the bottom of the list until you reached the limit of the spreadsheet (something like just over 1 million rows) without ever having to change the formula to reference a specific time period

Hope that makes sense