Why do we celebrate Mary on New Years Day? Isn't it a secular holiday?

On New Years Day, Catholics will celebrate the Solemnity of Mary, Mother of God, with a feast. This celebration is the octave of Christmas. An octave is an eight-day extension of the feast. In the modern Roman Calendar. This holiday is a celebration of Mary’s motherhood of Jesus. It is a reminder of the role she played in the salvation of humankind. The title “Mother of God” is a western derivation from the Greek Theotokos, which means “God-bearer”. Mary being chosen by God, the Father, to bring Jesus Christ into this world, and her willingness to do so is great cause for celebration. Without her role, Jesus would not have been able to die for the sins of humans, thus giving them a second chance at redemption. 
 
The honoring of Mary as the Mother of God can be traced back to the Council of Ephesus in 431. By the 7th century, January 1st was observed as a celebration of the Maternity of the Blessed Virgin Mary. In the 13th century, the Feast of the Circumcision of Christ had come to replace the feast honoring Mary. However, in 1751, Pope Benedict XIV allowed Portugal’s churches to devote a feast to Mary on the first Sunday in May. This was because of a push in Portugal for an official feast day celebrating Mary’s divine maternity. Eventually, the feast was expanded to include other countries. 
 
In 1914, the feast started to be observed on October 11. In 1931, Pope Pius XI extended the feast to the entire church. In 1974, Pope Paul VI removed the feast of the Circumcision of Christ from the liturgical calendar. He replaced it with the feast of the “Solemnity of Mary, Mother of God”, bringing Mary’s feast day back to the first day of the calendar year.