calculation between two report

[Anonymous]

Hi, 

I have a volume report used for months. Now we face a problem that we need to re-calculate the number of last year Dec and this year Jan. 

We prepared another report with volume amount and date column. Like below. 

Amount	Date
100	1/1/2020
200	1/2/2020
200	1/1/2019
...

I want to minus the amounts of the year/month of (date) from the current report. And then append these amount to previous month. Usually , it only happen for Jan every year. For example,  If the current report have 1000 (Volumes) for Jan 2020 , then we need to minus 300 from 1000 and append 300 to Dec last year. 

Do anyone have any idea how to do this? 

Thanks!

[AllisonKennedy]

@Anonymous
I don't fully understand your problem yet.
Where does your second report come from? How is the data source different or similar to the first report? What do the data source look like in their raw format?

What do you want to do with the 200 amount from Feb 2020 in the second report in your sample you have posted?

Do you always add to December of previous year, or just to previous month?

So for the example above, would we need to take the 200 from Feb 2020 and move that to Jan 2020? to Dec 2020? Or leave in Feb 2020?

Let us know some more info and we can offer up ideas.

[Anonymous]

@AllisonKennedy , 

The first report is the full report of volume including all years amounts. The second report which is only including the amount of Jan every year , is for adjustment to move the amounts from Jan to last year Dec. The second report data format is as below. 

Amount	Date
100	Jan/1/2020
200	Jan/2/2020
200	Jan/1/2019
...

For example , we have 300 in Jan 2020 and 200 in Jan 2019 . I want to move 300 to Dec 2019 and 200 to Dec 2018 of first report. 

Thank you for your kindly help 🙂