Back আনডেসিম্বর Bengali/Bangla Třináctý měsíc Czech Undecimber French Undecimber Japanese 13월 Korean Undecember Latin Undecimber Polish Undecimber Portuguese Тринадцатый месяц Russian Тринадцятий місяць Ukrainian
Undecimber or Undecember is a name for a thirteenth month in a calendar that normally has twelve months.