Maidyarem

The midwinter festival of Maidyarem celebrates the evolution of animals. The fifth Gahambar falls on days 286 through 290, typically December 31 to January 4.

Zoroastrians observe six seasonal festivals that celebrate the sanctity of God’s universal creations. Each Gahambar lasts five days and honors the five material creations: earth, water, plants, animals and humans. Believers spend the first four days reciting scriptures and come together on the last day for a feast.

Sourced from https://theguibordcenter.org/zoroastrian-holy-days-and-observances/