Summarize grouping by year and month

Question

I have a worksheet Movements with two fields:

mydate      | amount
2009-01-01  | 10.00
2009-01-02  | 13.00
2009-02-01  | 11.00
2009-02-05  | 12.00
2         


        

Answer 1

You need to use an array approach. How to combine arrays you can learn here https://stackoverflow.com/a/42488671/1393023

Foremost QUERY

It's simple and transparent

=QUERY(
  ARRAYFORMULA({TEXT(Movements!A:A,"YYYY-MM"),Movements!B:B}),
  "select Col1,sum(Col2) group by Col1"
)

Secondly ARRAYFORMULA(SUMIF)

Just combine the functions to a chain

=SORT(UNIQUE(FILTER(
  {
    TEXT(Movements!A2:A,"YYYY-MM"),
    SUMIF(EOMONTH(Movements!A2:A,1),EOMONTH(Movements!A2:A,1),Movements!B2:B)
  },
  LEN(Movements!B2:B)
)),1,1)

My example