Grouping data over many days into months

Hi guys,
Anyone know of a quick way to combine dates? I have a large data set with multiple variables organized by day. I would like to lump all of the daily cells into a single sum for the month.

Ex:

1/1/13 2
1/4/13 4
1/17/13 4
1/30/13 2

Should become

Jan 13 12

Simplying summing all of the cells for each month by adding a row and using the sum function is taking a very long time, any way to group the cells using an automated function?

Thanks

Select all your data and then on the Insert tab, click on Pivot Table. Drag the date column header into the Row Labels field and drag the amount into the values field. Click in the Pivot Table on one of the dates and Group. Group on Months and Years and the totals will be calculated for each month even if the year changes.

The dates have to be Excel recognizable dates and when you create the Pivot table, select a range longer than is required for your data otherwise grouping on the date may be difficult.

etaf,
This returns N/A after the first 4 cells. Any idea what that is going on?

thanks

etaf,
This returns N/A after the first 4 cells. Any idea what that is going on?

thanks

can we see a sample sheet ?

I can't attach a sample sheet because of my company. I do not understand the reference to column D in you forumula
=VALUE(TEXT(INDEX($A$2:$A$135, MATCH(0, COUNTIF($D$1:D1, TEXT($A$2:$A$135, "mmm-yyyy")), 0)), "mmm-yyyy"))

Once D1 changes to a cell that overlaps with a cell above it containing a date, it returns an incorrect date.

The file has the date, day month and year in column A and the value attached to each date in column B. I would like to sum all the values in column B that occur on the same month in the same year.

what column are you putting the formula into - thats the column you need to use

does the list start in row 2

found this if it helps http://www.get-digital-help.com/2010...ting-in-excel/
overlaps with a cell above it

I'm sorry, ignore that last problem. I am still getting a #value for e2. Here are the equations.

=VALUE(TEXT(INDEX($F$2:$F$135, MATCH(0, COUNTIF($N$1:N1, TEXT($F$2:$F$135, "mmm-yyyy")), 0)), "mmm-yyyy")) (entered as an array where, F is the date and N is the column w the equation)

=SUMPRODUCT((MONTH(F1:F100)&YEAR(F1:F100)=MONTH(N2)&YEAR(N2)),(I1:I100)) (Where I is the value column.) do you see an error?

Data Starts in row 2