[OS X TeX] semester calendars

[juan tolosa]

TeX has built in the commands \day, \month, \hear, from which one can, for example,
define \today. This is extremely convenient. 

However, I want to create a schedule of classes, say, for the fall 2015 semester,
that would start at say, Wednesday September 2, 2015, and would continue for
the entire semester, either for MWF classes, or for MW Thursday F classes.
In Excel this is easy to do, one just sets the initial date in the first cell and then
adds the appropriate number of integers. And I want this to remain fixed, even
if I were to re-typeset the file two years from today.

Is there a way to do this, similar to using the \today command? 
I don’t want to have to re-invent the wheel, and re-create
a “permanent calendar” from scratch.

Thanks,
              Juan