Chillai Kalan
Chillai Kalan or Chilla-i-Kalan (Persian: چلّه کلان, lit. 'Forty grand [days]') refers to a forty-day period of intense cold and harsh winter weather experienced annually from 21 December to 29 January, in the Kashmir Valley. It represents the coldest phase of winter in the region and has long held climatic, cultural, and social significance Chillai Kalan is followed by two shorter cold periods; Chill-i-Khurd (lit. 'forty small [days]'), a twenty-day phase from 30 January to 18 February, and Chill-i-Bachha (lit. 'forty baby [days]') which is from February 19 to February 28.