The word Chelle derives from the forty abbreviations of "forty" and merely indicates the passage of a given period of time (not necessarily forty days). The word "chelleh night" or "chelleh night", which is also used in popular culture as synonymous with Yalda Night, is from Yen that the first forty days of winter are called" Big chelleh "and twenty days after Yen are called" Little chelleh". And in the ancient timeline among the farmers had a division of forty. Chelle، two timeline situations during a solar year with the functions of popular culture one in summer Gaz (July) and the other in winter Gaz (January) each consists of two large (forty days) and small (twenty days) sections.