flask-babel error using Khmer locale

gistfile1.sh

>>> from flaskext.babel import refresh; refresh()
  >>> khmer = format_datetime(datetime(1987, 10, 10, 18, 00), 'full')
  Traceback (most recent call last):
    File "<stdin>", line 1, in <module>
    File "/Users/ashleyconnor/.virtualenvs/flask/lib/python2.7/site-packages/flaskext/babel.py", line 317, in format_datetime
      return _date_format(dates.format_datetime, datetime, format, rebase)
    File "/Users/ashleyconnor/.virtualenvs/flask/lib/python2.7/site-packages/flaskext/babel.py", line 382, in _date_format
      return formatter(obj, format, locale=locale, **extra)
    File "/Users/ashleyconnor/.virtualenvs/flask/lib/python2.7/site-packages/babel/dates.py", line 505, in format_datetime
      locale=locale)) \
    File "/Users/ashleyconnor/.virtualenvs/flask/lib/python2.7/site-packages/babel/dates.py", line 590, in format_time
      return parse_pattern(format).apply(time, locale)
    File "/Users/ashleyconnor/.virtualenvs/flask/lib/python2.7/site-packages/babel/dates.py", line 702, in apply
      return self % DateTimeFormat(datetime, locale)
    File "/Users/ashleyconnor/.virtualenvs/flask/lib/python2.7/site-packages/babel/dates.py", line 699, in __mod__
      return self.format % other
    File "/Users/ashleyconnor/.virtualenvs/flask/lib/python2.7/site-packages/babel/dates.py", line 760, in __getitem__
      return self.format_timezone(char, num)
    File "/Users/ashleyconnor/.virtualenvs/flask/lib/python2.7/site-packages/babel/dates.py", line 850, in format_timezone
      locale=self.locale)
    File "/Users/ashleyconnor/.virtualenvs/flask/lib/python2.7/site-packages/babel/dates.py", line 421, in get_timezone_name
      return get_timezone_location(dt_or_tzinfo, locale=locale)
    File "/Users/ashleyconnor/.virtualenvs/flask/lib/python2.7/site-packages/babel/dates.py", line 278, in get_timezone_location
      territory_name = locale.territories[territory]
    File "/Users/ashleyconnor/.virtualenvs/flask/lib/python2.7/site-packages/babel/localedata.py", line 195, in __getitem__
      orig = val = dict.__getitem__(self, key)
  KeyError: 'ZZ'
  >>> khmer = format_datetime(datetime(1987, 10, 10, 18, 00))
  >>> print(khmer.encode('utf8'))
  10 ១០ 1987, 18:00:00