generate_series() Interpretation

Hackers,

I'm curious about behavior such as this:

bric=# select generate_series('2011-05-31'::timestamp , '2012-04-01'::timestamp, '1 month');
generate_series
---------------------
2011-05-31 00:00:00
2011-06-30 00:00:00
2011-07-30 00:00:00
2011-08-30 00:00:00
2011-09-30 00:00:00
2011-10-30 00:00:00
2011-11-30 00:00:00
2011-12-30 00:00:00
2012-01-30 00:00:00
2012-02-29 00:00:00
2012-03-29 00:00:00

It seems to me that this is subject to interpretation. If I was building a calendaring app, for example, I might rather that the results were:

generate_series
---------------------
2011-05-31 00:00:00
2011-06-30 00:00:00
2011-07-31 00:00:00
2011-08-31 00:00:00
2011-09-30 00:00:00
2011-10-31 00:00:00
2011-11-30 00:00:00
2011-12-31 00:00:00
2012-01-31 00:00:00
2012-02-29 00:00:00
2012-03-31 00:00:00

Is there some way to change the interpretation of interval calculation like this? Or would I just have to write my own function to do it the way I want?

Thanks,

David