On July 6 each year, the Finns celebrate the birthday of Eino Leino, an outstanding poet who is considered one of the pioneers of the Finnish-language poetry. His birthday is a celebration of poetry and summer.

Eino Leino was born on July 6, 1878. He published his first poem when he was 12, and by age 18 had his first collection of poems published. Leino's talent was praised and loved by the critics. Leino also became an influential journalist.

After Finland gained independence, his idealistic political ideas collapsed, and his influence as a journalist weakened. But he was still writing poems and was publishing prolifically. In 1918, he was granted a State writer's pension.

Leino's most famous poem collections are Helkavirsiä (1903 and 1916). They are noted for the extensive use of Finnish folklore and mythology. The most frequent themes in Leino's poems are love, nature, and despair. Additionally, he made the first translation of Dante Alighieri's Divine Comedy into the Finnish language.

Leino's birthday on 6 July was named Eino Leino Day (Eino Leinon päivä) as well as day of Finnish poetry and summer in 1992, and it is an established Finnish flag day.