diff --git a/exec/period.hs b/exec/period.hs
--- a/exec/period.hs
+++ b/exec/period.hs
@@ -1,5 +1,6 @@
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE MultiWayIf #-}
+{-# LANGUAGE RecordWildCards #-}
 
 module Main where
 
@@ -8,18 +9,32 @@
 import qualified Data.Text.IO        as T
 import           Options.Applicative
 import           Text.Period
-
+import Text.PrettyPrint.ANSI.Leijen (string)
 import Prelude
 
 main :: IO ()
-main = execParser (info (helper <*> optParser) $ progDesc "period") >>= runCommand
+main = execParser (info (helper <*> optParser) $ progDescDoc (Just $ string desc)) >>= runCommand
+  where
+  desc = "Expand or collapse text representation of date range.\n\
+  \\n\
+  \period collapse 2018-01-01,2018-12-31\n\
+  \=> 2018\n\n\
+  \period collapse 2018-01-01,2118-12-31\n\
+  \=> 2018,2118\n\n\
+  \period expand 2018-01\n\
+  \=> 2018-01-01,2018-01-31\n\n\
+  \period expand 2018-01-07,14\n\
+  \=> 2018-01-07,2018-01-14\
+  \"
 
 data Command
-  = Collapse PeriodFmt T.Text
-  | Expand {
-    expandFmt :: PeriodFmt,
-    expandInput :: T.Text,
-    expandList :: Bool
+  = Collapse {
+    colFmt :: PeriodFmt,
+    colInput :: T.Text
+  } | Expand {
+    expFmt :: PeriodFmt,
+    expInput :: T.Text,
+    expList :: Bool
   }
 
 periodArg :: Parser T.Text
@@ -34,7 +49,6 @@
     short 'd' <> long "date-sep" <> value "," <>
     help "Start and end separator, by default ',' as in 'yyyy-mm-dd,yyyy-mm-dd'")
 
-
 mkCommand :: String -> String -> Parser Command -> Mod CommandFields Command
 mkCommand cmd desc parser =
   command cmd $ info (helper <*> parser) (progDesc desc)
@@ -48,9 +62,9 @@
   ]
 
 runCommand :: Command -> IO ()
-runCommand (Collapse fmt per) = T.putStrLn $ collapsePeriod fmt $ parsePeriod per
-runCommand (Expand fmt expandInput expandList) = if
-  | expandList -> T.putStr . T.unlines . map (collapsePeriod fmt . (\x -> (x, x))) $ uncurry enumFromTo p
-  | otherwise -> T.putStrLn $ formatPeriod fmt p
+runCommand Collapse{..} = T.putStrLn $ collapsePeriod colFmt $ parsePeriod colInput
+runCommand Expand{..} = if
+  | expList -> T.putStr . T.unlines . map (collapsePeriod expFmt . (\x -> (x, x))) $ uncurry enumFromTo p
+  | otherwise -> T.putStrLn $ formatPeriod expFmt p
   where
-  p = parsePeriod expandInput
+  p = parsePeriod expInput
diff --git a/period.cabal b/period.cabal
--- a/period.cabal
+++ b/period.cabal
@@ -1,11 +1,11 @@
 name:                period
-version:             0.1.0.6
+version:             0.1.0.7
 synopsis:            Parse and format date periods, collapse and expand their text representations.
--- description:
+description:         Library and executable to parse and format date periods, collapse and expand, e.g. 2018 → 2018-01-01,2018-12-31 and backwards.
 homepage:            https://github.com/w3rs/period
 license:             BSD3
 license-file:        LICENSE
-author:              Alexey Karakulov
+author:              Oleksii Karakulov
 maintainer:          ankarakulov@gmail.com
 -- copyright:
 category:            Text
@@ -47,7 +47,8 @@
                 period,
                 base,
                 text,
-                optparse-applicative
+                optparse-applicative,
+                ansi-wl-pprint
   GHC-options: -Wall -O2
 
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