bs/bse/cf/is: show local abbreviated month names on monthly columns

hledger-lib/Hledger/Data/Dates.hs

@@ -40,6 +40,7 @@ module Hledger.Data.Dates (
   parsedate,
   showDate,
   showDateSpan,
+  showDateSpanMonthAbbrev,
   elapsedSeconds,
   prevday,
   parsePeriodExpr,
@@ -110,6 +111,11 @@ showDate = formatTime defaultTimeLocale "%0C%y/%m/%d"
 showDateSpan :: DateSpan -> String
 showDateSpan = showPeriod . dateSpanAsPeriod
 
+-- | Like showDateSpan, but show month spans as just the abbreviated month name
+-- in the current locale.
+showDateSpanMonthAbbrev :: DateSpan -> String
+showDateSpanMonthAbbrev = showPeriodMonthAbbrev . dateSpanAsPeriod
+
 -- | Get the current local date.
 getCurrentDay :: IO Day
 getCurrentDay = do

hledger-lib/Hledger/Data/Period.hs

@@ -144,6 +144,13 @@ showPeriod (PeriodFrom b)      = formatTime defaultTimeLocale "%0C%y/%m/%d-" b
 showPeriod (PeriodTo e)        = formatTime defaultTimeLocale "-%0C%y/%m/%d" (addDays (-1) e)    -- -INCLUSIVEENDDATE
 showPeriod PeriodAll           = "-"
 
+-- | Like showPeriod, but if it's a month period show just 
+-- the 3 letter month name abbreviation for the current locale.
+showPeriodMonthAbbrev (MonthPeriod _ m)                           -- Jan
+  | m >= 0 && m < length monthnames = snd $ monthnames !! (m-1)
+  where monthnames = months defaultTimeLocale
+showPeriodMonthAbbrev p = showPeriod p
+
 periodStart :: Period -> Maybe Day
 periodStart p = mb
   where

hledger/Hledger/Cli/CompoundBalanceCommand.hs

@@ -408,7 +408,7 @@ compoundBalanceReportAsHtml ropts cbr =
          [tr_ $ th_ [colspanattr, leftattr] $ toHtml title]
       ++ [thRow $
           "" :
-          map showDateSpan colspans
+          map showDateSpanMonthAbbrev colspans
           ++ (if row_total_ ropts then ["Total"] else [])
           ++ (if average_ ropts then ["Average"] else [])
           ]