Today is the feast day of St. Catherine, patron saint of philosophers.
For a little bit about her life and why some churches celebrate St. Catherine’s day on the 24th, read this piece from the Greek Orthodox Archdiocese Online Chapel:
Saint Catherine, who was from Alexandria, was the daughter of Constas (or Cestus). She was an exceedingly beautiful maiden, most chaste, and illustrious in wealth, lineage, and learning. By her steadfast understanding, she utterly vanquished the passionate and unbridled soul of Maximinus, the tyrant of Alexandria; and by her eloquence, she stopped the mouths of the so-called philosophers who had been gathered to dispute with her. She was crowned with the crown of martyrdom in the year 305. Her holy relics were taken by Angels to the holy mountain of Sinai, where they were discovered many years later; the famous monastery of Saint Catherine was originally dedicated to the Holy Transfiguration of the Lord and the Burning Bush, but later was dedicated to Saint Catherine. According to the ancient usage, Saints Catherine and Mercurius were celebrated on the 24th of this month, whereas the holy Hieromartyrs Clement of Rome and Peter of Alexandria were celebrated on the 25th. The dates of the feasts of these Saints were interchanged at the request of the Church and Monastery of Mount Sinai, so that the festival of Saint Catherine, their patron, might be celebrated more festively together with the Apodosis of the Feast of the Entry of the Theotokos. The Slavic Churches, however, commemorate these Saints on their original dates.
A fuller account of her life can be found here.
Troparion of Great Martyr Katherine Tone 5
Let us praise Katherine, protectress of Sinai,
Bride of Christ and our helper.
With the sword of the Spirit she silenced the wisdom of the wicked.
She is crowned as a martyr and asks mercy for us all.
Kontakion of Great Martyr Katherine Tone 2
You lovers of martyrs raise a chorus now
in honour of wise Katherine.
She preached Christ in the stadium
and spat on the knowledge of philosophers.
Holy and Great Martyr, All-Wise Catherine, pray for us that we may take captive every thought to the obedience of Christ, and pray that we may be made worthy of the Kingdom of Heaven.