diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -22,3 +22,10 @@
 - Export `dayToYear` helper function since it is also used by the new module
 - Add tests
 - Enhance docs
+
+## [1.1.0.0] - 2024-03-19
+
+### Added
+
+- Add `ExtraHoliday` for Bundesland Berlin
+- Add and enhance docs
diff --git a/README.md b/README.md
--- a/README.md
+++ b/README.md
@@ -15,7 +15,9 @@
 There are even more public holidays in each federal state which
 are (partly) covered by the `ExtraHolidays` module of this package.
 
-See the module documentation for more information.
+See the [module documentation](https://hackage.haskell.org/package/bank-holiday-germany)
+on Hackage for more information.
+
 
 -----
 
diff --git a/bank-holiday-germany.cabal b/bank-holiday-germany.cabal
--- a/bank-holiday-germany.cabal
+++ b/bank-holiday-germany.cabal
@@ -1,7 +1,7 @@
 cabal-version:       3.6
 
 name:                bank-holiday-germany
-version:             1.0.0.2
+version:             1.1.0.0
 synopsis:            German bank holidays and public holidays
 description:         Calculation of bank holidays and most public holidays in Germany.
 homepage:            https://github.com/schoettl/bank-holiday-germany#readme
diff --git a/src/Data/Time/Calendar/BankHoliday/Germany.hs b/src/Data/Time/Calendar/BankHoliday/Germany.hs
--- a/src/Data/Time/Calendar/BankHoliday/Germany.hs
+++ b/src/Data/Time/Calendar/BankHoliday/Germany.hs
@@ -8,9 +8,23 @@
 holiday is also a legal holiday.
 
 Note: There are even more public holidays in each federal state which
-are covered by the [@ExtraHolidays@](Data.Time.Calendar.BankHoliday.Germany.ExtraHolidays)
+are covered by the [@ExtraHolidays@]("Data.Time.Calendar.BankHoliday.Germany.ExtraHolidays")
 module of this package.
 
+You can test this package or just calculate a few bank holidays with GHCi:
+
+@
+$ stack ghci --package time --package bank-holiday-germany
+ghci> import Data.Time
+ghci> import Data.Time.Calendar.BankHoliday.Germany
+ghci> isBankHoliday (fromGregorian 2024 5 1)  -- Tag der Arbeit
+True
+ghci> isPublicHoliday ChristmasEve
+False
+ghci> holidaysBetween (fromGregorian 2024 12 1) (fromGregorian 2024 12 26)
+[(2024-12-24,ChristmasEve),(2024-12-25,ChristmasDay),(2024-12-26,SecondChristmasDay)]
+@
+
 Resources:
 
  - https://de.wikipedia.org/wiki/Bankfeiertag
@@ -106,6 +120,11 @@
 
 -- | Compute 'Maybe' the holiday for a given date.
 --
+-- Note: In some years, two bank holidays can fall on the same
+-- day. E.g. 'LabourDay' and 'AscensionDay' in 2008 are both on
+-- 2008-05-01. In such cases this function returns the bank holiday
+-- that is defined first in the 'BankHoliday' 'Enum'.
+--
 -- >>> fromDay (fromGregorian 2024 1 1)
 -- Just NewYearsDay
 --
@@ -115,6 +134,10 @@
 fromDay day = listToMaybe $ filter (\d -> day == toDay (yearFromDay day) d) [minBound..maxBound]
 
 -- | Compute pairs of date and holiday from start to end.
+--
+-- Note: In some years, two bank holidays can fall on the same
+-- day. In such cases only one of them is in the resulting list.
+-- See 'fromDay' for more information.
 --
 -- >>> map snd $ holidaysBetween (fromGregorian 2024 12 25) (fromGregorian 2024 12 26)
 -- [ChristmasDay,SecondChristmasDay]
diff --git a/src/Data/Time/Calendar/BankHoliday/Germany/ExtraHolidays.hs b/src/Data/Time/Calendar/BankHoliday/Germany/ExtraHolidays.hs
--- a/src/Data/Time/Calendar/BankHoliday/Germany/ExtraHolidays.hs
+++ b/src/Data/Time/Calendar/BankHoliday/Germany/ExtraHolidays.hs
@@ -2,7 +2,7 @@
 {-|
 
 This module provides additional German public holidays that are not
-covered by the [bank holidays](Data.Time.Calendar.BankHoliday.Germany).
+covered by the [bank holidays]("Data.Time.Calendar.BankHoliday.Germany").
 
 Public holidays – except for
 'Data.Time.Calendar.BankHoliday.Germany.GermanUnityDay' – are under
@@ -13,7 +13,7 @@
 But there are some additional extra holidays which may differ between
 federal states.
 
-For example Heilige Drei Könige is not a bank holiday but it is a
+For example, Heilige Drei Könige is not a bank holiday but it is a
 public holiday in Bavaria.
 
 Note: The extra holidays are currently only implemented for Bavaria.
@@ -22,24 +22,57 @@
 Miesbach, Oberbayern) in the next couple years:
 
 @
-  import Data.List
-  import Data.Time
-  import qualified Data.Time.Calendar.BankHoliday.Germany as BH
-  import qualified Data.Time.Calendar.BankHoliday.Germany.ExtraHolidays as EH
+import Prelude
+import Data.List
+import Data.Time
+import qualified Data.Time.Calendar.BankHoliday.Germany as BH
+import qualified Data.Time.Calendar.BankHoliday.Germany.ExtraHolidays as EH
 
-  start = fromGregorian 2024 1 1
+start = fromGregorian 2024 1 1
 
-  end = fromGregorian 2026 12 31
+end = fromGregorian 2025 12 31
 
-  holidays :: [[String]]
-  holidays = map (\(x,y) -> [show x, BH.germanHolidayName y]) (filter (BH.isPublicHoliday . snd) $ BH.holidaysBetween start end)
-          ++ map (\(x,y) -> [show x, EH.germanHolidayName y]) (filter ((/=EH.Friedensfest) . snd) $ EH.holidaysBetween EH.Bayern start end)
+holidays :: [[String]]
+holidays = map (\(x,y) -> [show x, BH.germanHolidayName y]) (filter (BH.isPublicHoliday . snd) $ BH.holidaysBetween start end)
+        ++ map (\(x,y) -> [show x, EH.germanHolidayName y]) (filter ((/= EH.Friedensfest) . snd) $ EH.holidaysBetween EH.Bayern start end)
 
-  putStrLn $ unlines $ sort $ map unwords holidays
+main :: IO ()
+main = putStrLn $ unlines $ sort $ map unwords holidays
 @
 
+@
+2024-01-01 Neujahrstag
+2024-01-06 Heilige Drei Könige
+2024-03-29 Karfreitag
+2024-04-01 Ostermontag
+2024-05-01 Tag der Arbeit
+2024-05-09 Christi Himmelfahrt
+2024-05-20 Pfingstmontag
+2024-05-30 Fronleichnam
+2024-08-15 Mariä Himmelfahrt
+2024-10-03 Tag der Deutschen Einheit
+2024-11-01 Allerheiligen
+2024-12-25 1. Weihnachtsfeiertag
+2024-12-26 2. Weihnachtsfeiertag
+2025-01-01 Neujahrstag
+2025-01-06 Heilige Drei Könige
+2025-04-18 Karfreitag
+2025-04-21 Ostermontag
+2025-05-01 Tag der Arbeit
+2025-05-29 Christi Himmelfahrt
+2025-06-09 Pfingstmontag
+2025-06-19 Fronleichnam
+2025-08-15 Mariä Himmelfahrt
+2025-10-03 Tag der Deutschen Einheit
+2025-11-01 Allerheiligen
+2025-12-25 1. Weihnachtsfeiertag
+2025-12-26 2. Weihnachtsfeiertag
+@
+
 Resources:
 
+ - Übersicht: https://de.wikipedia.org/wiki/Gesetzliche_Feiertage_in_Deutschland
+ - Weitere Übersicht: https://www.arbeitstage.org/
  - Bayern: https://www.stmi.bayern.de/suv/feiertage/
 
 -}
@@ -90,6 +123,7 @@
   | Friedensfest           -- ^ Friedensfest (Bayern (Augsburg), …)
   | MariaeHimmelfahrt      -- ^ Mariä Himmelfahrt (Bayern (regional), …)
   | Allerheiligen          -- ^ Allerheiligen (Bayern, …)
+  | InternationalerFrauentag -- ^ Internationaler Frauentag (Berlin, …)
   deriving (Enum, Eq, Bounded, Show, Read)
 
 -- | Compute the date for a given year and extra holiday.
@@ -102,6 +136,7 @@
 toDay year Friedensfest            = fromGregorian year 8 8
 toDay year MariaeHimmelfahrt       = fromGregorian year 8 15
 toDay year Allerheiligen           = fromGregorian year 11 1
+toDay year InternationalerFrauentag = fromGregorian year 3 8
 
 -- | Compute 'Maybe' the holiday for a given date.
 --
@@ -128,6 +163,7 @@
   Friedensfest           -> "Friedensfest"
   MariaeHimmelfahrt      -> "Mariä Himmelfahrt"
   Allerheiligen          -> "Allerheiligen"
+  InternationalerFrauentag -> "Internationaler Frauentag"
 
 -- | Check if 'ExtraHoliday' is a holiday in the given federal state.
 --
@@ -142,4 +178,5 @@
 isHolidayInState Bayern Friedensfest = True
 isHolidayInState Bayern MariaeHimmelfahrt = True
 isHolidayInState Bayern Allerheiligen = True
+isHolidayInState Berlin InternationalerFrauentag = True
 isHolidayInState _ _ = False
diff --git a/test/Main.hs b/test/Main.hs
--- a/test/Main.hs
+++ b/test/Main.hs
@@ -2,6 +2,7 @@
 module Main (main) where
 
 import Data.Time.Calendar.BankHoliday.Germany
+import Data.Time.Calendar.BankHoliday.Germany.ExtraHolidays (ExtraHoliday(..), FederalState(..))
 import Data.Time.Calendar.BankHoliday.Germany.ExtraHolidays qualified as EH
 import Data.Time.Calendar.WeekDate
 import Data.Time
@@ -71,17 +72,20 @@
    describe "Data.Time.Calendar.BankHoliday.Germany.ExtraHolidays" $ do
      describe "FederalState" $
        it "has right number of states" $
-         length [minBound .. maxBound :: EH.FederalState] `shouldBe` 16
+         length [minBound .. maxBound :: FederalState] `shouldBe` 16
      describe "toDay" $
        it "works for Fronleichnam (depending on Easter Sunday)" $ do
          -- https://www.arbeitstage.org/feiertage/fronleichnam/
-         map (\y -> show $ EH.toDay y EH.Fronleichnam) [2024..2027]
+         map (\y -> show $ EH.toDay y Fronleichnam) [2024..2027]
            `shouldBe` ["2024-05-30", "2025-06-19", "2026-06-04", "2027-05-27"]
      describe "holidaysBetween" $ do
        it "only has Bavaria's extra holidays" $
-         map snd (EH.holidaysBetween EH.Bayern (day 2024 11 1) (day 2024 12 31))
-           `shouldBe` [EH.Allerheiligen]
+         map snd (EH.holidaysBetween Bayern (day 2024 11 1) (day 2024 12 31))
+           `shouldBe` [Allerheiligen]
+       it "there is only one extra holiday in Berlin" $ do
+         filter (EH.isHolidayInState Berlin) [minBound..maxBound]
+           `shouldBe` [InternationalerFrauentag]
        it "has no holidays for other states yet => otherwise, please add tests" $ do
-         let statesExceptBavaria = filter (/=EH.Bayern) [minBound..maxBound]
+         let statesExceptBavaria = filter (not . flip elem [Bayern, Berlin]) [minBound..maxBound]
          let holidays = concatMap (\x -> EH.holidaysBetween x (day 2024 1 1) (day 2024 12 31)) statesExceptBavaria
          holidays `shouldBe` []