diff --git a/CHANGES.md b/CHANGES.md
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,3 +1,8 @@
+# Version 0.3
+
+  * Year can have less then 4 digits
+
+
 # Version 0.2 (2016-12-14)
 
   * ISO formatter
diff --git a/README.md b/README.md
--- a/README.md
+++ b/README.md
@@ -3,8 +3,7 @@
 
 # Welcome to Text Time library
 
-This library contains fast parser and formatter for iso dates in Text.
-
+This library contains fast parser and formatter for iso dates between UTCTime and Text types.
 
 
 ## Installation
@@ -15,7 +14,6 @@
 stack test
 ```
 
-
 # Join in!
 
 We are happy to receive bug reports, fixes, documentation enhancements,
@@ -31,4 +29,4 @@
 
 # Redistributing
 
-bytestring-time source code is distributed under the BSD3 License.
+text-time source code is distributed under the BSD3 License.
diff --git a/src/Data/Text/Time/Parse.hs b/src/Data/Text/Time/Parse.hs
--- a/src/Data/Text/Time/Parse.hs
+++ b/src/Data/Text/Time/Parse.hs
@@ -1,5 +1,6 @@
--- | This code is adapted from sqlite-simple package
+{-# LANGUAGE OverloadedStrings #-}
 
+-- | This code is adapted from sqlite-simple package
 module Data.Text.Time.Parse
     ( parseISODateTime
     , parseUTCTimeOrError
@@ -53,7 +54,6 @@
 getDay :: A.Parser Day
 getDay = do
     yearStr <- A.takeWhile isDigit
-    when (T.length yearStr < 4) (fail "year must consist of at least 4 digits")
 
     let year = toNum yearStr
     month <- (A.char '-' *> digits "month") <|> pure 1
diff --git a/test-src/Data/Text/TimeSpec.hs b/test-src/Data/Text/TimeSpec.hs
--- a/test-src/Data/Text/TimeSpec.hs
+++ b/test-src/Data/Text/TimeSpec.hs
@@ -1,11 +1,16 @@
 {-# LANGUAGE OverloadedStrings #-}
 module Data.Text.TimeSpec (spec) where
 
-import Data.Text.Time
-import Test.Hspec
+import Data.Text.Lazy (toStrict)
 import Data.Time
+import Data.Time.Calendar.MonthDay
+import Test.Hspec
+import Test.QuickCheck
 
+import Data.Text.Time
 
+
+
 spec :: Spec
 spec = do
 
@@ -14,6 +19,9 @@
     it "iso format: YYYY" $ do
         parseISODateTime "2014" `shouldBe` UTCTime (fromGregorian 2014 1 1) 0
 
+    it "iso format: YYYY" $ do
+        parseISODateTime "98" `shouldBe` UTCTime (fromGregorian 98 1 1) 0
+
     it "iso format: YYYY-MM" $ do
         parseISODateTime "2014-04" `shouldBe` UTCTime (fromGregorian 2014 4 1) 0
 
@@ -34,3 +42,17 @@
     it "to iso" $ do
         formatISODateTime (UTCTime (fromGregorian 2014 1 1) 13513) `shouldBe` "2014-01-01T03:45:13"
 
+
+  describe "Invariants" $ do
+
+    it "is inverse to show" $ property $
+        \x -> (parseISODateTime . toStrict . formatISODateTime) x == (x :: UTCTime)
+
+
+instance Arbitrary UTCTime where
+  arbitrary = do
+      year <- choose (0, 10^4) :: Gen Integer
+      month <- choose (1, 12) :: Gen Int
+      day <- choose (1, monthLength False month) :: Gen Int
+      seconds <- choose (0, 86399) :: Gen Int
+      return $ UTCTime (fromGregorian year month day) (realToFrac seconds)
diff --git a/text-time.cabal b/text-time.cabal
--- a/text-time.cabal
+++ b/text-time.cabal
@@ -1,5 +1,5 @@
 name:           text-time
-version:        0.2.0
+version:        0.3.1
 synopsis:       Library for Time parsing from Text into UTCTime
 License:        BSD3
 License-file:   LICENSE
@@ -45,7 +45,7 @@
                     base >= 4 && <5,
                     hspec >=2 && <3,
                     QuickCheck >=2.6 && <3,
-                    Cabal >=1.16.0 && <2,
+                    Cabal >=1.16.0 && <4,
                     attoparsec < 0.14,
                     formatting < 7,
                     text < 2,