In the manual it seems you would create months as simple elements rather than string elements. My initial inclination would have been to create months as string considering they are not numeric but textual. Thoughts?
I think you need to have both a re-read of the manual and a re-think. In TM1 dimensions all element names are strings regardless of whether the element name is "1" or "JAN". The element type on the other hand has absolutely nothing to do with the name or ID of the element but everything to do with the type of data which will be stored in the cell intersections marked by the element. S is for string data, N is for numeric data (which is what you are going to want 99.9% of the time.)
Bear in mind also that although element type is defined on a per dimension basis that what really matters is the data type of the cube cell and this is determined by the element type of the LAST dimension in the cube.