Microsoft recommended patching period - Security Patch release and updates

Ideally a security patch released by a vendor such as Microsoft for the Windows OS is required to be patched immediately. What would be the recommended patching period that Microsoft or best practices would require by which the systems should be updated? Microsoft as I understand releases patches every second Tuesday of the month as a cycle. Accommodating the time to test those patches against applications within the user environment should 30 days from the date of release for a medium level risk be a reasonable upper limit set for carrying out the patching?

Any suggestions or recommendations are highly appreciated.