In OpenOffice (or Excel), I need to calculate the exact number of days that a certain date range falls within a certain year. Eg. the date range 2009/1/1 to 2010/11/01 has 365 days in 2009 and 305 days in 2010. So far it seems a function days_in_year(year;startdate;enddate) does not exist and doing something similar in a formula using WHEN would be quite a long formular.

Does anybody know something small for this purpose (without macros)?