In Judaism, the New Moon ushers in a new month

Rosh Chodesh or Rosh ḥodesh (Hebrew: ראש חודש‎; trans. Beginning of the Month; lit. Head of the Month) is the name for the first day of every month in the Hebrew calendar, marked by the appearance of the new moon. The new moon is marked by the day and hour that the new crescent is observed. It is considered a minor holiday, akin to the intermediate days of Passover and Sukkot.^[1]

Navratri, Navaratri, or Navarathri (Hindi: नवरात्रि; Gujarati: નવરાત્રી; Tamil: நவராத்திரி; Sanskrit: नवरात्रम्; Marathi: नवरात्र; Punjabi: ਨਰਾਤੇ Nepali: नवरात्रि; Bengali: নবরাত্রি; Kannada: ನವರಾತ್ರಿ; Telugu: దుర్గా నవరాత్రులు; Malayalam: നവരാത്രി; Tulu: ನವರಾತ್ರಿ/നവരാത്രി) is a Hindu festival of worship of Shakti and dance & festivities. The word Navaratri literally means nine nights in Sanskrit, nava meaning nine and ratri meaning nights^[2]. During these nine nights and ten days, nine forms of Shakti/Devi are worshiped. The 10th day is commonly referred to as Vijayadashami or Dussehra.

The beginning of spring and the beginning of autumn are two very important junctions of climatic and solar influence. These two periods are taken as sacred opportunities for the worship of the Divine Mother. The dates of the festival are determined according to the lunar calendar.