Maidyoi-shema

Believers observe the midsummer festival of Maidyoi-shema on days 101 to 105 of the year, typically June 29 to July 3. It celebrates the creation of water, the spring harvest’s end, and the start of the summer harvest.

Zoroastrians observe six seasonal festivals (Gahambar) 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/