Creating clone channel using "spacewalk-clone-by-date" command fails with error, even if the correct channel label is passed

Issue

• While cloning a rhn-tools-rhel-x86_64-server-6 using spacewalk-clone-by-date command to a channel label starting with rhn- fails with error :

# spacewalk-clone-by-date -l rhn-tools-rhel-x86_64-server-6 rhn-tools-rhel-x86_64-server-6-$(date +%Y-%m-%d)

Cloning rhn-tools-rhel-x86_64-server-6 to rhn-tools-rhel-x86_64-server-6-2015-05-11 with original package set.
Traceback (most recent call last):
  File "/usr/bin/spacewalk-clone-by-date", line 412, in <module>
    sys.exit(abs(main() or 0))
  File "/usr/bin/spacewalk-clone-by-date", line 402, in main
    return cloneByDate.main(args)
  File "/usr/share/rhn/utils/cloneByDate.py", line 245, in main
    cloner.create_channels(options.skip_depsolve)
  File "/usr/share/rhn/utils/cloneByDate.py", line 384, in create_channels
    dest, dest_parent[0])
  File "/usr/share/rhn/utils/cloneByDate.py", line 917, in clone_channel
    details, True)
  File "/usr/lib64/python2.6/xmlrpclib.py", line 1199, in __call__
    return self.__send(self.__name, args)
  File "/usr/lib64/python2.6/xmlrpclib.py", line 1489, in __request
    verbose=self.__verbose
  File "/usr/lib64/python2.6/xmlrpclib.py", line 1253, in request
    return self._parse_response(h.getfile(), sock)
  File "/usr/lib64/python2.6/xmlrpclib.py", line 1392, in _parse_response
    return u.close()
  File "/usr/lib64/python2.6/xmlrpclib.py", line 838, in close
    raise Fault(**self._stack[0])
xmlrpclib.Fault: <Fault 1200: "redstone.xmlrpc.XmlRpcFault: Channel name must be at least 6 characters long, begin with a letter and may contain only lowercase letters, hyphens ('-'), periods ('.'), underscores ('_'), numerals, spaces, parentheses and forward slashes ('/').">