can you make calendars in Inkscape?

Inkscape doesn't allow you to work on multi page documments.

AFAIK there is no allowance for multi-page docs in the SVG spec?

Scribus (http://www.scribus.net/) has a script to aid in the creation of calendars - that might be what you're looking for.

CALENDAR:

You can make a multi-month calendar, via the extensions menu

>Extensions >Render >Calendar...

default settings will give you the current year's 12 month calendar.

http://tavmjong.free.fr/INKSCAPE/MANUAL/html/Extensions-Render.html#Extensions-Calendar

MULTI-PAGE DOCS:
  You can export multiple objects/groups/etc as their own png files. In this case the object would be each month of a given year.. Each Month would be part of a export feature titled "BATCH" exporting.

  At the bottom of the >File >Export Bitmap... Dialog (Shft+Ctrl+E) there is an option for:
              [_] Batch export n selected objects

  The "Batch" export will be available if more than one object on your drawing (canvas) is selected. If checked [Enabled], each of the selected objects will be exported into its own file.

  The name of the file will be the id name for the object. To set the ID of an object simply [right+click] the object (group the items that make up a specific month) and select >Object Properties (Shift+Ctrl+O). The text you place in the Id: field will be the filename and the directory will be the current file location. Best thing to do is 'save' your file in the desired directory before you assign Id's to BATCH export objects.

 BATCH export documentation
http://tavmjong.free.fr/INKSCAPE/MANUAL/html/File-Export.html#File-Export-PNG.

Another method of multi-page (slide-show) exporting is via the Jessyink extension, >Extensions >JessyInk. This method makes use of the layer feature within Inkscape.