Today is the feast of the Immaculate Heart of Mary.  This short history of the Feast is courtesy of Catholic Fire:

Historically, regular devotion to the Immaculate Heart of Mary can be traced back to the twelfth century in the writings of St. Anselm and St. Bernard of Clairvaux.   St. Bernardine of Siena also promoted this devotion in the fifteenth century.   St. John Eudes and his followers began celebrating the feast of the Pure Heart of Mary on February 8, 1643 -- two decades before the liturgical feast of the Sacred Heart of Jesus was celebrated.   In the nineteenth century, Popes Pius VII and Pius IX permitted several churches to celebrate the feast of the Pure Heart of Mary.   The apparitions at Fatima in 1917 emphasized the devotion of the Immaculate Heart of Mary as Refuge of Sinners.  Mary requested that Russia be consecrated to her Immaculate Heart. In response to this request, Pope Pius XII, consecrated the world to our Blessed Mother (1942) and established the feast of the Immaculate Heart of Mary for the whole Church, so as to obtain by her intercession "peace among nations, freedom for the Church, the conversion of sinners, the love of purity and the practice of virtue" (Decree of May 4, 1944).

St. Francis, on the Immaculate Heart of Mary:

“Immaculate Heart of Mary, cause of our joy, pray for us.”

A devotional practice for the Feast of the Immaculate Heart of Mary:

The Immaculate Heart of Mary is traditionally represented with seven wounds, for "the Seven Dolors of the Blessed Virgin Mary."  The following, courtesy of EWTN, is a prayer suitable for the Feast.

The Seven Dolors of the Blessed Virgin Mary

V: O God, come to my assistance; R: O Lord, make hast to help me V: Glory be to the Father..... R: As it was in the beginning.... 1. I grieve for you, O Mary, most sorrowful, in the affliction of your tender heart at the prophecy of the holy and aged Simeon. Dear Mother, by your heart so afflicted, obtain for me the virtue of humility and the gift of the holy fear of God. " Hail Mary........ " 2. I grieve for you, O Mary most sorrowful, in the anguish of your most affectionate heart during the flight into Egypt and your sojourn there. Dear Mother, by your heart so troubled, obtain for me the virtue of generosity, especially toward the poor, and the gift of piety. " Hail Mary........ " 3. I grieve for you, O Mary most sorrowful, in those anxieties which tried your troubled heart at the loss of your dear Jesus. Dear Mother, by your heart so full of anguish, obtain for me the virtue of chastity and the gift of knowledge. " Hail Mary........ " 4. I grieve for you, O Mary most sorrowful, in the consternation of your heart at meeting Jesus as He carried His cross. Dear Mother, by your heart so troubled, obtain for me the virtue of patience and the gift of fortitude. " Hail Mary........ " 5. I grieve for you, O Mary most sorrowful, in the martyrdom which your generous heart endured in standing near Jesus in His agony. Dear Mother, by your afflicted heart, obtain for me the virtue of temperance and the gift of counsel. " Hail Mary........ " 6. I grieve for you, O Mary most sorrowful, in the wounding of your compassionate heart, when the side of Jesus was struck by the lance before His Body was removed from the cross. Dear Mother, by your heart thus transfixed, obtain for me the virtue of fraternal charity and the gift of understanding. " Hail Mary........ " 7. I grieve for you, O Mary most sorrowful, for the pangs that wrenched your most loving heart at the burial of Jesus. Dear Mother, by your heart sunk in the bitterness of desolation, obtain for me the virtue of diligence and the gift of wisdom. " Hail Mary........ " Let Us Pray Let intercession be made for us, we beseech You, O Lord Jesus Christ, now and at the Hour of our death, before the throne of Your mercy, by the Blessed Virgin Mary, Your Mother, whose most holy soul was pierced by a sword of sorrow in the hour of Your bitter Passion. Through You, O Jesus Christ, Saviour of the world, Who with the Father and the Holy Ghost lives and reigns world without end. Amen.