Expand month abbreviations.

This is done by bibtex2html, but not bib2bib.

HakyllBibTex.hs

@@ -50,6 +50,7 @@ bibEntryContext = Context $ \key _ item ->
             Nothing  -> empty
             Just val -> case key of
                 "author" -> return $ StringField $ formatAuthors val
+                "month"  -> return $ StringField $ expandMonth val
                 _        -> return $ StringField $ latexToHtml val
 
 --------------------------------------------------------------------------------
@@ -99,6 +100,22 @@ formatAuthor = intercalate " "
                . reverse
                . (splitOn ",")
 
+--------------------------------------------------------------------------------
+expandMonth :: String -> String
+expandMonth mon = case mon of
+    "jan" -> "January"
+    "feb" -> "February"
+    "mar" -> "March"
+    "apr" -> "April"
+    "may" -> "May"
+    "jun" -> "June"
+    "jul" -> "July"
+    "aug" -> "August"
+    "sep" -> "September"
+    "oct" -> "October"
+    "nov" -> "November"
+    "dec" -> "December"
+
 --------------------------------------------------------------------------------
 -- Inefficient...
 trimSpace :: String -> String