diff --git a/ChangeLog.md b/ChangeLog.md
deleted file mode 100644
--- a/ChangeLog.md
+++ /dev/null
@@ -1,3 +0,0 @@
-# Changelog for korea-holidays
-
-## Unreleased changes
diff --git a/korea-holidays.cabal b/korea-holidays.cabal
--- a/korea-holidays.cabal
+++ b/korea-holidays.cabal
@@ -4,15 +4,15 @@
 --
 -- see: https://github.com/sol/hpack
 --
--- hash: f38259eef1c2f67a41fc49b224e7408e8596a6f8568a509f9fc893bc7b39fdcb
+-- hash: 1ff53d702584511d74ad7fbc539d9d7d85ff9658bf45d65dd41dff59e67d4310
 
 name:           korea-holidays
-version:        0.1.0.3
+version:        0.1.0.4
 synopsis:       Korea Holidays
 description:    Please see the README on GitHub at <https://github.com/kkweon/korea-holidays#readme>
 category:       Time
-homepage:       https://github.com/githubuser/korea-holidays#readme
-bug-reports:    https://github.com/githubuser/korea-holidays/issues
+homepage:       https://github.com/kkweon/korea-holidays#readme
+bug-reports:    https://github.com/kkweon/korea-holidays/issues
 author:         Kyung Mo Kweon
 maintainer:     kkweon@gmail.com
 copyright:      2019 Kyung Mo Kweon
@@ -21,13 +21,12 @@
 build-type:     Simple
 extra-source-files:
     README.md
-    ChangeLog.md
 data-files:
     data/ko_holidays.yaml
 
 source-repository head
   type: git
-  location: https://github.com/githubuser/korea-holidays
+  location: https://github.com/kkweon/korea-holidays
 
 library
   exposed-modules:
@@ -44,6 +43,7 @@
     , monad-extras
     , split
     , template-haskell
+    , time
     , yaml
   default-language: Haskell2010
 
@@ -64,5 +64,6 @@
     , monad-extras
     , split
     , template-haskell
+    , time
     , yaml
   default-language: Haskell2010
diff --git a/src/Data/Holiday/Korea.hs b/src/Data/Holiday/Korea.hs
--- a/src/Data/Holiday/Korea.hs
+++ b/src/Data/Holiday/Korea.hs
@@ -11,29 +11,35 @@
 -}
 module Data.Holiday.Korea where
 
-import           Data.Aeson.Types               ( FromJSON
-                                                , (.:)
-                                                , parseJSON
-                                                , withObject
-                                                )
-import           Data.Holiday.Model             ( Date(..)
-                                                , Holiday(..)
-                                                )
-import           Data.Maybe                     ( fromJust
-                                                , listToMaybe
-                                                )
-import           Util.Config                    ( holidays )
+import Data.Holiday.Model (Date(..), Holiday(..))
+import Data.Maybe (listToMaybe)
+import Util.Config (holidays)
 
+import Control.Monad (msum)
+
+import qualified Data.Time as Time
+
 -- | 'getHoliday' returns Nothing if there is no Korean holiday.
-getHoliday
-  :: Integer -- ^ Year
+getHoliday ::
+     Integer -- ^ Year
   -> Int -- ^ Month
   -> Int -- ^ Day
   -> Maybe Holiday
 getHoliday year month day = listToMaybe $ filter match holidays
- where
-  match :: Holiday -> Bool
-  match Holiday { date = YMD (y, m, d) } | y == year && m == month && d == day =
-    True
-  match Holiday { date = MD (m, d) } | m == month && d == day = True
-  match _ = False
+  where
+    match :: Holiday -> Bool
+    match Holiday {date = YMD (y, m, d)}
+      | y == year && m == month && d == day = True
+    match Holiday {date = MD (m, d)}
+      | m == month && d == day = True
+    match _ = False
+
+-- | `getNearestHoliday` returns a nearest holiday within a year range
+getNearestHoliday :: Time.Day -> Maybe Holiday
+getNearestHoliday day = msum . map go $ [0 .. 365]
+  where
+    go :: Integer -> Maybe Holiday
+    go delta =
+      let newDay = Time.addDays delta day
+          (y, m, d) = Time.toGregorian newDay
+       in getHoliday y m d
diff --git a/src/Data/Holiday/Model.hs b/src/Data/Holiday/Model.hs
--- a/src/Data/Holiday/Model.hs
+++ b/src/Data/Holiday/Model.hs
@@ -16,22 +16,15 @@
 module Data.Holiday.Model
   ( Date(..)
   , Holiday(..)
-  )
-where
+  ) where
 
-import           Control.Monad.Extra            ( liftMaybe )
-import           Data.Aeson.Types               ( FromJSON
-                                                , Parser
-                                                , (.:)
-                                                , (.:?)
-                                                , parseJSON
-                                                , withObject
-                                                )
-import           Data.List.Split                ( splitOn )
-import           Data.Maybe                     ( fromMaybe )
-import           GHC.Generics                   ( Generic )
-import           Language.Haskell.TH.Syntax     ( Lift )
-import           Text.Read                      ( readMaybe )
+import Control.Monad.Extra (liftMaybe)
+import Data.Aeson.Types (FromJSON, (.:), parseJSON, withObject)
+import Data.List.Split (splitOn)
+import Data.Maybe (fromMaybe)
+import GHC.Generics (Generic)
+import Language.Haskell.TH.Syntax (Lift)
+import Text.Read (readMaybe)
 
 data Date
   = YMD (Integer, Int, Int) -- ^ (Year, Month, Day) Some Holiday has a different date every year
@@ -39,10 +32,12 @@
   deriving (Show, Eq, Lift)
 
 -- | 'Holiday' represents the date of holiday and the name of holiday.
-data Holiday = Holiday
-  { date :: Date -- ^ Date of the holiday
-  , name :: String -- ^ Name of the holiday
-  } deriving (Show, Eq, Generic, Lift)
+data Holiday =
+  Holiday
+    { date :: Date -- ^ Date of the holiday
+    , name :: String -- ^ Name of the holiday
+    }
+  deriving (Show, Eq, Generic, Lift)
 
 instance FromJSON Holiday where
   parseJSON =
@@ -53,32 +48,40 @@
         liftMaybe $ parseKoreanDate s
 
 parseKoreanDate :: String -> Maybe Date
-parseKoreanDate xs = case splitOn "-" xs of
-  [y, m, d] | verifyYmd y m d -> Just $ YMD (read y, read m, read d)
-  [m, d] | verifyMd m d       -> Just $ MD (read m, read d)
-  _                           -> Nothing
+parseKoreanDate xs =
+  case splitOn "-" xs of
+    [y, m, d]
+      | verifyYmd y m d -> Just $ YMD (read y, read m, read d)
+    [m, d]
+      | verifyMd m d -> Just $ MD (read m, read d)
+    _ -> Nothing
 
 verifyYmd :: String -> String -> String -> Bool
-verifyYmd y m d = fromMaybe False $ do
-  year  <- readMaybe y :: Maybe Integer
-  month <- readMaybe m :: Maybe Int
-  day   <- readMaybe d :: Maybe Int
-  return $ isValidYear year && isValidMonth month && isValidDay day
+verifyYmd y m d =
+  fromMaybe False $ do
+    year <- readMaybe y :: Maybe Integer
+    month <- readMaybe m :: Maybe Int
+    day <- readMaybe d :: Maybe Int
+    return $ isValidYear year && isValidMonth month && isValidDay day
 
 verifyMd :: String -> String -> Bool
-verifyMd m d = fromMaybe False $ do
-  month <- readMaybe m :: Maybe Int
-  day   <- readMaybe d :: Maybe Int
-  return $ isValidMonth month && isValidDay day
+verifyMd m d =
+  fromMaybe False $ do
+    month <- readMaybe m :: Maybe Int
+    day <- readMaybe d :: Maybe Int
+    return $ isValidMonth month && isValidDay day
 
 isValidYear :: Integer -> Bool
-isValidYear y | 1900 <= y && y <= 3000 = True
-              | otherwise              = False
+isValidYear y
+  | 1900 <= y && y <= 3000 = True
+  | otherwise = False
 
 isValidMonth :: Int -> Bool
-isValidMonth m | 1 <= m && m <= 12 = True
-               | otherwise         = False
+isValidMonth m
+  | 1 <= m && m <= 12 = True
+  | otherwise = False
 
 isValidDay :: Int -> Bool
-isValidDay d | 1 <= d && d <= 31 = True
-             | otherwise         = False
+isValidDay d
+  | 1 <= d && d <= 31 = True
+  | otherwise = False
diff --git a/src/Util/Config.hs b/src/Util/Config.hs
--- a/src/Util/Config.hs
+++ b/src/Util/Config.hs
@@ -2,8 +2,8 @@
 
 module Util.Config where
 
-import           Data.Yaml.TH                   ( decodeFile )
-import qualified Data.Holiday.Model            as K
+import qualified Data.Holiday.Model as K
+import Data.Yaml.TH (decodeFile)
 
 holidays :: [K.Holiday]
 holidays = $$(decodeFile "data/ko_holidays.yaml")
diff --git a/test/Data/Holiday/KoreaSpec.hs b/test/Data/Holiday/KoreaSpec.hs
--- a/test/Data/Holiday/KoreaSpec.hs
+++ b/test/Data/Holiday/KoreaSpec.hs
@@ -1,31 +1,32 @@
 module Data.Holiday.KoreaSpec where
 
-import qualified Data.Holiday.Korea            as Korea
-import qualified Data.Holiday.Model            as KM
+import qualified Data.Holiday.Korea as Korea
+import qualified Data.Holiday.Model as KM
 
-import           Data.Holiday.Model             ( date
-                                                , name
-                                                )
-import           Test.Hspec                     ( Spec
-                                                , describe
-                                                , it
-                                                , shouldBe
-                                                )
+import qualified Data.Time as Time
 
+import Data.Holiday.Model (date, name)
+import Test.Hspec (Spec, describe, it, shouldBe)
+
 spec :: Spec
-spec = describe "Data.Holiday.Korea" $ do
-  it "returns New Year's Day when 2000/1/1"
-    $          Korea.getHoliday 2000 1 1
-    `shouldBe` Just KM.Holiday {date = KM.MD (1, 1), name = "New Year's Day"}
-  it "returns March 1 Movement Day when 2019/3/1"
-    $          Korea.getHoliday 2019 3 1
-    `shouldBe` Just KM.Holiday
-                 { date = KM.MD (3, 1)
-                 , name = "March 1 Movement Day"
-                 }
-  it "returns Chuseok when 2029/09/22"
-    $          Korea.getHoliday 2029 9 22
-    `shouldBe` Just KM.Holiday {date = KM.YMD (2029, 9, 22), name = "Chuseok"}
-  it "returns Nothing when it's not a Holiday 2019/07/04"
-    $          Korea.getHoliday 2019 7 4
-    `shouldBe` Nothing
+spec =
+  describe "Data.Holiday.Korea" $ do
+    it "returns New Year's Day when 2000/1/1" $
+      Korea.getHoliday 2000 1 1 `shouldBe`
+      Just KM.Holiday {date = KM.MD (1, 1), name = "New Year's Day"}
+    it "returns March 1 Movement Day when 2019/3/1" $
+      Korea.getHoliday 2019 3 1 `shouldBe`
+      Just KM.Holiday {date = KM.MD (3, 1), name = "March 1 Movement Day"}
+    it "returns Chuseok when 2029/09/22" $
+      Korea.getHoliday 2029 9 22 `shouldBe`
+      Just KM.Holiday {date = KM.YMD (2029, 9, 22), name = "Chuseok"}
+    it "returns Nothing when it's not a Holiday 2019/07/04" $
+      Korea.getHoliday 2019 7 4 `shouldBe` Nothing
+    it "returns a nearest holiday when is given 2029/09/21" $
+      let day = Time.fromGregorian 2029 9 21
+       in Korea.getNearestHoliday day `shouldBe`
+          Just KM.Holiday {date = KM.YMD (2029, 9, 22), name = "Chuseok"}
+    it "returns a exact holiday when it's 2019/3/1" $
+      let day = Time.fromGregorian 2019 3 1
+       in Korea.getNearestHoliday day `shouldBe`
+          Just KM.Holiday {date = KM.MD (3, 1), name = "March 1 Movement Day"}