Presenting all months in a year in a Pivot Table/Chart when allmonths are not included in source dat

[tms]

Excel 2007, Windows 7

I'm creating a series of pivot tables and charts to show price data by
month in a given year for different categories of products (in
different locations). If I have entries for most but not all months
in a given year, is it possible to have excel render a table and chart
that displays all 12 months of the calendar year even though not all
are included in the source data? As it works by default, it only
presents data for those months that are included in the source data.

I know a work around would be to include the missing months with a
blank entry in the source data, but given the large number of
categories and geographic locations I'll be doing this for, this would
be somewhat time consuming. Or after generating the pivot tables, I
could copy and paste the tables as values, and then generate the
charts I want from that. That will be time consuming as well, but
will work if I need it to.

Is anyone aware of a way to do this via a setting in Excel that would
have it recognize that I'm trying to present a calendar year's worth
of data for each year included?

thanks in advance - T