diff --git a/gclient.py b/gclient.py
index 9a678220f..28f590d90 100644
--- a/gclient.py
+++ b/gclient.py
@@ -339,6 +339,40 @@ class Dependency(GClientKeywords, gclient_utils.WorkItem):
   def run(self, revision_overrides, command, args, work_queue, options):
     """Runs 'command' before parsing the DEPS in case it's a initial checkout
     or a revert."""
+
+    def maybeGetParentRevision(options):
+      """If we are performing an update and --transitive is set, set the
+      revision to the parent's revision. If we have an explicit revision
+      do nothing."""
+      if command == 'update' and options.transitive and not options.revision:
+        _, revision = gclient_utils.SplitUrlRevision(self.parsed_url)
+        if not revision:
+          options.revision = revision_overrides.get(self.parent.name)
+          if options.verbose and options.revision:
+            print("Using parent's revision date: %s" % options.revision)
+          # If the parent has a revision override, then it must have been
+          # converted to date format.
+          assert (not options.revision or
+                  gclient_utils.IsDateRevision(options.revision))
+
+    def maybeConvertToDateRevision(options):
+      """If we are performing an update and --transitive is set, convert the
+      revision to a date-revision (if necessary). Instead of having
+      -r 101 replace the revision with the time stamp of 101 (e.g.
+      "{2011-18-04}").
+      This way dependencies are upgraded to the revision they had at the
+      check-in of revision 101."""
+      if (command == 'update' and
+          options.transitive and
+          options.revision and
+          not gclient_utils.IsDateRevision(options.revision)):
+        revision_date = scm.GetRevisionDate(options.revision)
+        revision = gclient_utils.MakeDateRevision(revision_date)
+        if options.verbose:
+          print("Updating revision override from %s to %s." %
+                (options.revision, revision))
+        revision_overrides[self.name] = revision
+
     assert self._file_list == []
     if not self.should_process:
       return
@@ -362,8 +396,10 @@ class Dependency(GClientKeywords, gclient_utils.WorkItem):
         # Create a shallow copy to mutate revision.
         options = copy.copy(options)
         options.revision = revision_overrides.get(self.name)
+        maybeGetParentRevision(options)
         scm = gclient_scm.CreateSCM(self.parsed_url, self.root_dir(), self.name)
         scm.RunCommand(command, options, args, self._file_list)
+        maybeConvertToDateRevision(options)
         self._file_list = [os.path.join(self.name, f.strip())
                            for f in self._file_list]
     self.processed = True
@@ -1043,6 +1079,11 @@ def CMDsync(parser, args):
                          'has multiple solutions configured and will work even '
                          'if the src@ part is skipped. Note that specifying '
                          '--revision means your safesync_url gets ignored.')
+  parser.add_option('-t', '--transitive', action='store_true',
+                    help='When a revision is specified (in the DEPS file or '
+                          'with the command-line flag), transitively update '
+                          'the dependencies to the date of the given revision. '
+                          'Only supported for SVN repositories.')
   parser.add_option('-H', '--head', action='store_true',
                     help='skips any safesync_urls specified in '
                          'configured solutions and sync to head instead')
diff --git a/gclient_scm.py b/gclient_scm.py
index 6dc4da7f6..99461d13f 100644
--- a/gclient_scm.py
+++ b/gclient_scm.py
@@ -126,6 +126,13 @@ class SCMWrapper(object):
 class GitWrapper(SCMWrapper):
   """Wrapper for Git"""
 
+  def GetRevisionDate(self, revision):
+    """Returns the given revision's date in ISO-8601 format (which contains the
+    time zone)."""
+    # TODO(floitsch): get the time-stamp of the given revision and not just the
+    # time-stamp of the currently checked out revision.
+    return self._Capture(['log', '-n', '1', '--format=%ai'])
+
   @staticmethod
   def cleanup(options, args, file_list):
     """'Cleanup' the repo.
@@ -186,6 +193,14 @@ class GitWrapper(SCMWrapper):
     if not revision:
       revision = default_rev
 
+    if gclient_utils.IsDateRevision(revision):
+      # Date-revisions only work on git-repositories if the reflog hasn't
+      # expired yet. Use rev-list to get the corresponding revision.
+      #  git rev-list -n 1 --before='time-stamp' branchname
+      if options.transitive:
+        print('Warning: --transitive only works for SVN repositories.')
+        revision = default_rev
+
     rev_str = ' at %s' % revision
     files = []
 
@@ -668,6 +683,13 @@ class GitWrapper(SCMWrapper):
 class SVNWrapper(SCMWrapper):
   """ Wrapper for SVN """
 
+  def GetRevisionDate(self, revision):
+    """Returns the given revision's date in ISO-8601 format (which contains the
+    time zone)."""
+    date = scm.SVN.Capture(['propget', '--revprop', 'svn:date', '-r', revision,
+                            os.path.join(self.checkout_path, '.')])
+    return date.strip()
+
   def cleanup(self, options, args, file_list):
     """Cleanup working copy."""
     self._Run(['cleanup'] + args, options)
diff --git a/gclient_utils.py b/gclient_utils.py
index 995322389..81a1f667e 100644
--- a/gclient_utils.py
+++ b/gclient_utils.py
@@ -112,6 +112,17 @@ def SplitUrlRevision(url):
   return tuple(components)
 
 
+def IsDateRevision(revision):
+  """Returns true if the given revision is of the form "{ ... }"."""
+  return bool(revision and re.match(r'^\{.+\}$', str(revision)))
+
+
+def MakeDateRevision(date):
+  """Returns a revision representing the latest revision before the given
+  date."""
+  return "{" + date + "}"
+
+
 def SyntaxErrorToError(filename, e):
   """Raises a gclient_utils.Error exception with the human readable message"""
   try:
diff --git a/tests/gclient_scm_test.py b/tests/gclient_scm_test.py
index d7d93b678..a11c4d7cb 100755
--- a/tests/gclient_scm_test.py
+++ b/tests/gclient_scm_test.py
@@ -82,7 +82,7 @@ class SVNWrapperTestCase(BaseTestCase):
 
   def testDir(self):
     members = [
-        'FullUrlForRelativeUrl', 'RunCommand',
+        'FullUrlForRelativeUrl', 'GetRevisionDate', 'RunCommand',
         'cleanup', 'diff', 'export', 'pack', 'relpath', 'revert',
         'revinfo', 'runhooks', 'status', 'update',
         'updatesingle', 'url',
@@ -543,7 +543,7 @@ from :3
 
   def testDir(self):
     members = [
-        'FullUrlForRelativeUrl', 'RunCommand',
+        'FullUrlForRelativeUrl', 'GetRevisionDate', 'RunCommand',
         'cleanup', 'diff', 'export', 'pack', 'relpath', 'revert',
         'revinfo', 'runhooks', 'status', 'update', 'url',
     ]
diff --git a/tests/gclient_smoketest.py b/tests/gclient_smoketest.py
index acd0ab566..408cd66b0 100755
--- a/tests/gclient_smoketest.py
+++ b/tests/gclient_smoketest.py
@@ -327,6 +327,43 @@ class GClientSmokeSVN(GClientSmokeBase):
     tree['src/svn_hooked1'] = 'svn_hooked1'
     self.assertTree(tree)
 
+  def testSyncTransitive(self):
+    # TODO(maruel): safesync.
+    if not self.enabled:
+      return
+    self.gclient(['config', self.svn_base + 'trunk/src/'])
+
+    # Make sure we can populate a new repository with --transitive.
+    self.parseGclient(
+        ['sync', '--transitive', '--revision', 'src@1', '--deps', 'mac',
+          '--jobs', '1'],
+        ['running', 'running', 'running', 'running'])
+    tree = self.mangle_svn_tree(
+        ('trunk/src@1', 'src'),
+        ('trunk/third_party/foo@1', 'src/third_party/fpp'),
+        ('trunk/other@1', 'src/other'),
+        ('trunk/third_party/foo@1', 'src/third_party/prout'))
+
+    # Get up to date, so we can test synching back.
+    self.gclient(['sync', '--deps', 'mac', '--jobs', '1'])
+
+    # Manually remove svn_hooked1 before synching to make sure it's not
+    # recreated.
+    os.remove(join(self.root_dir, 'src', 'svn_hooked1'))
+
+    self.parseGclient(
+        ['sync', '--transitive', '--revision', 'src@1', '--deps', 'mac',
+          '--delete_unversioned_trees', '--jobs', '1'],
+        ['running', 'running', 'running', 'running', 'deleting'])
+    tree = self.mangle_svn_tree(
+        ('trunk/src@1', 'src'),
+        ('trunk/third_party/foo@1', 'src/third_party/fpp'),
+        ('trunk/other@1', 'src/other'),
+        ('trunk/third_party/foo@1', 'src/third_party/prout'))
+    tree['src/file/other/DEPS'] = (
+        self.FAKE_REPOS.svn_revs[2]['trunk/other/DEPS'])
+    self.assertTree(tree)
+
   def testSyncIgnoredSolutionName(self):
     """TODO(maruel): This will become an error soon."""
     if not self.enabled:
diff --git a/tests/gclient_utils_test.py b/tests/gclient_utils_test.py
index f0d833bd3..59d5eb7d0 100755
--- a/tests/gclient_utils_test.py
+++ b/tests/gclient_utils_test.py
@@ -28,8 +28,8 @@ class GclientUtilsUnittest(GclientUtilBase):
         'CheckCall', 'CheckCallError', 'CheckCallAndFilter',
         'CheckCallAndFilterAndHeader', 'Error', 'ExecutionQueue', 'FileRead',
         'FileWrite', 'FindFileUpwards', 'FindGclientRoot',
-        'GetGClientRootAndEntries', 'MakeFileAutoFlush',
-        'MakeFileAnnotated', 'PathDifference', 'Popen',
+        'GetGClientRootAndEntries', 'IsDateRevision', 'MakeDateRevision',
+        'MakeFileAutoFlush', 'MakeFileAnnotated', 'PathDifference', 'Popen',
         'PrintableObject', 'RemoveDirectory', 'SoftClone', 'SplitUrlRevision',
         'SyntaxErrorToError', 'WorkItem',
         'errno', 'hack_subprocess', 'logging', 'os', 'Queue', 're', 'rmtree',