A family of Microsoft relational database management systems designed for ease of use.
oschl,
First of all, Project can do planning on a monthly basis, BUT, in Project there is only one definition for a "month" (i.e. Project does not plan in calendar months). You can get close by using "emons" (elapsed months) but even that uses a fixed 30 days per month regardless of the calendar month.
If you want to get exact and schedule by actual calendar months, it can be done, but it requires the use of some VBA.
For reference, Project schedules everything down to the minute, regardless of the units the user has chosen to display in the Duration field.
Hope this helps.
John