diff --git a/Data/X509/AlgorithmIdentifier.hs b/Data/X509/AlgorithmIdentifier.hs
--- a/Data/X509/AlgorithmIdentifier.hs
+++ b/Data/X509/AlgorithmIdentifier.hs
@@ -55,6 +55,8 @@
         , ([1,2,840,113549,1,1,2], SignatureALG HashMD2 PubKeyALG_RSA)
         , ([1,2,840,113549,1,1,11], SignatureALG HashSHA256 PubKeyALG_RSA)
         , ([1,2,840,113549,1,1,12], SignatureALG HashSHA384 PubKeyALG_RSA)
+        , ([1,2,840,113549,1,1,13], SignatureALG HashSHA512 PubKeyALG_RSA)
+        , ([1,2,840,113549,1,1,14], SignatureALG HashSHA224 PubKeyALG_RSA)
         , ([1,2,840,10040,4,3],    SignatureALG HashSHA1 PubKeyALG_DSA)
         , ([1,2,840,10045,4,3,1],  SignatureALG HashSHA224 PubKeyALG_ECDSA)
         , ([1,2,840,10045,4,3,2],  SignatureALG HashSHA256 PubKeyALG_ECDSA)
diff --git a/Data/X509/Cert.hs b/Data/X509/Cert.hs
--- a/Data/X509/Cert.hs
+++ b/Data/X509/Cert.hs
@@ -12,7 +12,7 @@
 module Data.X509.Cert (Certificate(..)) where
 
 import Data.ASN1.Types
-import Data.Hourglass (DateTime)
+import Data.Hourglass (DateTime, TimezoneOffset(TimezoneOffset))
 import Control.Applicative ((<$>), (<*>))
 import Data.X509.Internal
 import Data.X509.PublicKey
@@ -41,7 +41,7 @@
         , certSerial       :: Integer                -- ^ Serial number
         , certSignatureAlg :: SignatureALG           -- ^ Signature algorithm
         , certIssuerDN     :: DistinguishedName      -- ^ Issuer DN
-        , certValidity     :: (DateTime, DateTime)   -- ^ Validity period
+        , certValidity     :: (DateTime, DateTime)   -- ^ Validity period (UTC)
         , certSubjectDN    :: DistinguishedName      -- ^ Subject DN
         , certPubKey       :: PubKey                 -- ^ Public key
         , certExtensions   :: Extensions             -- ^ Extensions
@@ -104,8 +104,8 @@
         eAlgId    = toASN1 (certSignatureAlg cert) []
         eIssuer   = toASN1 (certIssuerDN cert) []
         (t1, t2)  = certValidity cert
-        eValidity = asn1Container Sequence [ASN1Time TimeGeneralized t1 Nothing
-                                           ,ASN1Time TimeGeneralized t2 Nothing]
+        eValidity = asn1Container Sequence [ASN1Time TimeGeneralized t1 (Just (TimezoneOffset 0))
+                                           ,ASN1Time TimeGeneralized t2 (Just (TimezoneOffset 0))]
         eSubject  = toASN1 (certSubjectDN cert) []
         epkinfo   = toASN1 (certPubKey cert) []
         eexts     = toASN1 (certExtensions cert) []
diff --git a/Tests/Tests.hs b/Tests/Tests.hs
--- a/Tests/Tests.hs
+++ b/Tests/Tests.hs
@@ -56,6 +56,8 @@
         , SignatureALG HashMD2 PubKeyALG_RSA
         , SignatureALG HashSHA256 PubKeyALG_RSA
         , SignatureALG HashSHA384 PubKeyALG_RSA
+        , SignatureALG HashSHA512 PubKeyALG_RSA
+        , SignatureALG HashSHA224 PubKeyALG_RSA
         , SignatureALG HashSHA1 PubKeyALG_DSA
         , SignatureALG HashSHA224 PubKeyALG_ECDSA
         , SignatureALG HashSHA256 PubKeyALG_ECDSA
diff --git a/x509.cabal b/x509.cabal
--- a/x509.cabal
+++ b/x509.cabal
@@ -1,5 +1,5 @@
 Name:                x509
-Version:             1.5.0.1
+Version:             1.5.1
 Description:         X509 reader and writer
 License:             BSD3
 License-file:        LICENSE