[rs 2]The longest and darkest night of the year is a time when friends and family gather together to eat, drink and read poetry (especially Hafez) and Shahnameh until well after midnight.

The poems of Divan-e Hafez, which can be found in the bookcases of most Iranian families, are read or recited on various occasions such as this festival and Nowruz.

In the first century, significant numbers of Eastern Christians were settled in Parthian and Sasanian territories, where they had received protection from religious persecution.

Ancient peoples such as the Aryans and Indo-Europeans were well attuned to natural phenomena such as the changing of seasons, as their daily activities were dictated by the availability of sunlight, while their crops were impacted by climate and weather.

In Zoroastrian tradition the longest and darkest night of the year was a particularly inauspicious day, and the practices of what is now known as "Shab-e Chelleh/Yalda" were originally customs intended to protect people from evil (see dews) during that long night,[rs 7] at which time the evil forces of Ahriman were imagined to be at their peak.

[rs 1] Although the religious significance of the long dark night has been lost, the old traditions of staying up late in the company of friends and family have been retained in Iranian culture to the present day.

[rs 10] Razi based his hypothesis on the fact that some of the poetry of the early Islamic era refers to Mihragan in connection with snow and cold.

For instance, it is believed that consuming watermelons on the night of Chelleh will ensure the health and well-being of the individual during the months of summer by protecting him from falling victim to excessive heat or disease produced by hot humors.

In Khorasan, there is a belief that whoever eats carrots, pears, pomegranates, and green olives will be protected against the harmful bite of insects, especially scorpions.

Another favorite and prevalent pastime of the night of Chelleh is fāl-e Ḥāfeẓ, which is divination using the Dīvān of Hafez (i.e. bibliomancy).

[rs 2] Activities common to the festival include staying up past midnight, conversation, drinking, reading poems out loud, telling stories and jokes, and, for some, dancing.

Another tradition is giving dried fruits and nuts and gift to family and friends specially to the bride, wrapped in tulle and tied with ribbon (similar to wedding and shower "party favors") in khorasan giving gift to the bride was obligatory.