diff --git a/LICENSE b/LICENSE
--- a/LICENSE
+++ b/LICENSE
@@ -1,4 +1,4 @@
-Copyright (c) 2011 Peter Simons <simons@cryp.to>
+Copyright (c) 2012 Joachim Breitner
 All rights reserved.
 
 Redistribution and use in source and binary forms, with or without
@@ -12,7 +12,7 @@
       disclaimer in the documentation and/or other materials provided
       with the distribution.
 
-    * Neither the name of Peter Simons nor the names of other
+    * Neither the name of Joachim Breitner nor the names of other
       contributors may be used to endorse or promote products derived
       from this software without specific prior written permission.
 
diff --git a/Main.hs b/Main.hs
--- a/Main.hs
+++ b/Main.hs
@@ -113,8 +113,8 @@
     exitFailure
 
   thisDay <- getCurrentDay
-  let firstDay = minimum $ map transactionEffectiveDate ts
-  let lastDay = maximum $ map transactionEffectiveDate ts
+  let firstDay = minimum $ map transactionDate2 ts
+  let lastDay = maximum $ map transactionDate2 ts
   let existingSpan = DateSpan (Just firstDay) (Just lastDay)
 
   let begin = maybe firstDay (fixSmartDateStr' thisDay) (optBegin opts)
@@ -129,16 +129,16 @@
 
   forM_ spans $ \(DateSpan (Just ibegin) (Just iend)) -> do
       let preQuery = And [ Acct (optInvAcc opts),
-                           EDate (openClosedSpan Nothing (Just ibegin))]
+                           Date (openClosedSpan Nothing (Just ibegin))]
           pre_amount = negate $ unMix $ accountAmount preQuery ts
       let prefix = (ibegin, pre_amount)
 
-      let eQuery = And [Acct (optInvAcc opts), EDate (openClosedSpan Nothing (Just iend))]
+      let eQuery = And [Acct (optInvAcc opts), Date (openClosedSpan Nothing (Just iend))]
       let final = unMix $ accountAmount eQuery ts
       let postfix = (iend, final)
 
       let cfQuery = And [ Not (Or [Acct (optInvAcc opts), Acct (optInterestAcc opts)]), 
-                          EDate (openClosedSpan (Just ibegin) (Just iend)) ] 
+                          Date (openClosedSpan (Just ibegin) (Just iend)) ] 
       let cf = calculateCashFlow cfQuery ts
 
       let totalCF = sortBy (comparing fst) $ filter ((/=0) . aquantity . snd) $ prefix : cf ++ [postfix]
@@ -180,7 +180,7 @@
 calculateCashFlow :: Query -> [Transaction] -> CashFlow
 calculateCashFlow query = map go
     where
-    go t = (transactionEffectiveDate t, amt)
+    go t = (transactionDate2 t, amt)
         where
         amt = sum $
               map (unMix . pamount) $ filter (matchesPosting query) $
diff --git a/hledger-irr.cabal b/hledger-irr.cabal
--- a/hledger-irr.cabal
+++ b/hledger-irr.cabal
@@ -1,5 +1,5 @@
 Name:                   hledger-irr
-Version:                0.1
+Version:                0.1.1
 Synopsis:               computes the internal rate of return of an investment
 License:                BSD3
 License-file:           LICENSE
@@ -64,11 +64,11 @@
  > 2011/04/01: €-50.00
  > 2011/05/01: €47.00
  > 2011/06/01: €90.00
- > 2011/01/01 - 2012/12/07: 17.72%
+ > 2011/01/01 - 2013/05/02: 17.72%
  > $ hledger-irr -f speculation.ledger -t "Rate Gain" -i Speculation -e 2011-03-01
  > 2011/01/01 - 2011/03/01: 26.11%
  > $ hledger-irr -f speculation.ledger -t "Rate Gain" -i Speculation -b 2011-03-01
- > 2011/03/01 - 2012/12/07: 12.28%
+ > 2011/03/01 - 2013/05/02: 12.27%
  > $ hledger-irr -f speculation.ledger -t "Rate Gain" -i Speculation --monthly
  > 2011/01/01 - 2011/02/01: 12.43%
  > 2011/02/01 - 2011/03/01: 41.57%
@@ -104,7 +104,7 @@
 
 Executable hledger-irr
   Main-is:              Main.hs
-  Build-depends:        base >= 3 && < 5, hledger-lib >= 0.19.3, time, Cabal, statistics >= 0.10
+  Build-depends:        base >= 3 && < 5, hledger-lib == 0.20 || == 0.20.0.*, time, Cabal, statistics >= 0.10
   Ghc-Options:          -Wall
 
 source-repository head