If you need to derive the previous month from a known date, use this formula:
=DATE(YEAR(A1);MONTH(A1)-1;1)
This works in OpenOffice (and LibreOffice), which do not seem to have a native function to do the job, and should work in MS Office Excel as well.
It seems Excel still can’t tell me the days in a particular month.
The following formula works, though:
=DAY(DATE(YEAR(A1),MONTH(A1)+1,1)-1)
Obviously, A1 has to have a date in it.
Works like a charm:
Update, much, much later: Looks like LibreOffice has a DAYSINMONTH function.
OpenOffice.org doesn’t seem to have any built-in functions for cube roots, but there’s an easy workaround. To find the nth root, use powers to the nth fraction. Probably easier to illustrate than to explain with my rusty math skills. 😉
I mean this:
You need to use the brackets because otherwise the power would take precedence over the division.
Yesterday, I had the problem that a number range I entered in a table (“3-4”) was changed into a date by OpenOffice. Never saw that happen before, I think it must be a new functionality. I tried to switch it off but found nothing in the Auto Correction options. The developers put the option in a weird spot:
A loud “Hooray” for weird defaults.