I'd consider using a pivottable.

You can group by month and year and show averages (or sums or max or...)

If you've never used pivottables, here are a few links:

Debra Dalgleish's pictures at Jon Peltier's site:
http://peltiertech.com/Excel/Pivots/pivottables.htm
And Debra's own site:
http://www.contextures.com/xlPivot01.html

John Walkenbach also has some at:
http://j-walk.com/ss/excel/files/general.htm
(look for Tony Gwynn's Hit Database)

Chip Pearson keeps Harald Staff's notes at:
http://www.cpearson.com/excel/pivots.htm

MS has some at (xl2000 and xl2002):
http://office.microsoft.com/downloads/2000/XCrtPiv.aspx
http://office.microsoft.com/assistan...lconPT101.aspx

===========
Depending on how your data is laid out, you could use a bunch of formulas:

=average(if(text(a2:a1000,"yyyymm")="200710",b2:b1 000))
This is an array formula. Hit ctrl-shift-enter instead of enter. If you do it
correctly, excel will wrap curly brackets {} around your formula. (don't type
them yourself.)

And you can't use the whole column until xl2007.

=========
Or you could add a helper column to your data:
=text(a2,"yyyymm")
(and drag down)
Then sort your data by this the helper column.
Then apply data|subtotals, choose average for the field you want.
(xl2003 menu system)

wrote:

My VBA knowledge is fairly basic so I'm looking more for an answer
than help with developing the code.

I typically have data files with 1 data point per weekday that will
sometimes be 15 years long. I would like to have a macro that will
give me a series of monthly averages of the daily data for each month.
Obviously I can do it manually by entering the average function for
each month's daily data range, but going thru 15 years of daily data,
with a different number of weekdays in each month, to calculate a
monthly average for each is a pain. Any suggestions or help would be
greatly appreciated.

Thanks

--

Dave Peterson