diff --git a/.gitignore b/.gitignore
index 55e4dfd..3523b86 100644
--- a/.gitignore
+++ b/.gitignore
@@ -120,3 +120,5 @@ noarch/
 /tzdata2014j.tar.gz
 /tzcode2015a.tar.gz
 /tzdata2015a.tar.gz
+/tzcode2015b.tar.gz
+/tzdata2015b.tar.gz
diff --git a/sources b/sources
index ea4a2a7..aecff55 100644
--- a/sources
+++ b/sources
@@ -1,4 +1,4 @@
 6a3392cd5f1594d13c12c1a836ac8d91  javazic.tar.gz
 cfc79fbbb17f21052d3dd7634ec70bea  javazic-1.8-37392f2f5d59.tar.xz
-8f375ede46ae137fbac047ac431bda37  tzcode2015a.tar.gz
-4ed11c894a74a5ea64201b1c6dbb8831  tzdata2015a.tar.gz
+f073a7c9bca7f9fe408491f826e92968  tzcode2015b.tar.gz
+75571bb17c7b6be88a9f8872e45bc726  tzdata2015b.tar.gz
diff --git a/tzdata.spec b/tzdata.spec
index 2df7ade..9de5a0e 100644
--- a/tzdata.spec
+++ b/tzdata.spec
@@ -1,8 +1,8 @@
 Summary: Timezone data
 Name: tzdata
-Version: 2015a
-%define tzdata_version 2015a
-%define tzcode_version 2015a
+Version: 2015b
+%define tzdata_version 2015b
+%define tzcode_version 2015b
 Release: 1%{?dist}
 License: Public Domain
 Group: System Environment/Base
@@ -117,6 +117,14 @@ rm -rf $RPM_BUILD_ROOT
 %{_datadir}/javazi-1.8
 
 %changelog
+* Wed Mar 25 2015 Patsy Franklin <pfrankli@redhat.com> - 2015b-1
+- Rebase to 2015b
+  - Mongolia will start observing DST again this year, from the last
+    Saturday in March at 02:00 to the last Saturday in September at 00:00.
+  - Palestine will start DST on March 28, not March 27.  Also,
+    correct the fall 2014 transition from September 26 to October 24.
+    Adjust future predictions accordingly.
+
 * Thu Feb 12 2015 Patsy Franklin <pfrankli@redhat.com> - 2015a-1
 - Rebase to 2015a
   - New leap second 2015-06-30 23:59:60 UTC as per IERS Bulletin C 49.