“Let us all joy in the Lord, celebrating the festal day in honor of Blessed Mary the Virgin, for whose Nativity the Angels rejoice and co-laud the Son of God”―thus do the progenies of the Prophet St. Elias [the Carmelites] and St. Dominic invite the faithful at the Introit of today’s Mass proper to their Missals to pay adoration and thanksgiving unto the Lord and Savior with sacred cheer this day on account of the ineffable loving-kindness He has manifested in “the Nativity of the glorious Virgin Mary, of the seed of Abraham, arisen of the tribe of Juda, out of the illustrious lineage of David” (1st Antiphon at Vespers). It behooves us, and exceedingly so, to joyfully render all praise and thanksgiving to the Lord for the eternal and infinite charity wherewith He has loved the little Maiden of Nazareth whom He had predestined from all eternity to be the Virgin Mother of His only-begotten Son, as the Lesson from the Book of Proverbs in today’s Mass typically depicts. The great Benedictine scholar, His Eminence Alfredo Ildelfonso Schuster, Cardinal Archbishop of Milan, of happy memory, writes upon the sublimity and profundity of this sacred day in his great work The Sacramentary (Liber Sacramentorum): Historical and Liturgical Notes on the Roman Missal, [Vol. V (Parts 8 and 9); trans. Arthur Levelis-Marke and W. Fairfax-Cholmeley; New York: Benziger Brothers, 1930]:  

As Eve, our first Mother, arose from the side of Adam, dazzling with life and innocence, so Mary came forth, bright and immaculate from the heart of the eternal Word, who, by the co-operation of the Holy Spirit, as the Liturgy teaches us, was pleased to form that body and soul which were to be, one day, his Tabernacle and altar. This is the sublime meaning of the feast of the Birthday of the Blessed Virgin Mary. It is the dawn foretelling the day which already breaks behind the eternal hills, the mystic rod which rises from the venerable  root of Jesse; the stream which springs from Paradise; it is the symbolical fleece which is stretched on our dry earth to catch the miraculous dew. This is the new Eve, that is to say the life and the Mother of all the living, who is born to-day for those to whom the first Eve became the Mother of sin and death.

Pondering on such joyous marvels of grace, truly can we cry forth in rapt adoration with St. Paul, "O depth of the riches of the wisdom and of the knowledge of God: how incomprehensible are His judgments, and His ways unsearchable!" (Rom. cap. xi., 33).

Therefore does the great St. Augustine exhort us to pious cheerfulness in the Second Nocturn of Matins, “Let our land laugh and sing with merriment, bathed in the glory of this great Virgin's rising.” Not only on account of the glory of Jesus and Mary should we be overcome by devout gladness in contemplating this sacred Mystery, but also because of the inestimable graces that this sacred Nativity brought to the round orb of the earth:

Eve wept, but Mary laughed. Eve's womb was big with tears, but Mary's womb was big with gladness. Eve gave birth to a sinner, but Mary gave birth to the sinless One. The mother of our race brought punishment into the world, but the Mother of our Lord brought salvation into the world. Eve was the foundress of sin, but Mary was the foundress of righteousness. Eve welcomed death, but Mary helped in life. Eve smote, but Mary healed. For Eve's disobedience, Mary offered obedience; and for Eve's unbelief, Mary offered faith.

In her beautiful work of liturgical poetry Symphonia harmoniæ cælestium revelationum, St. Hildegarde of Bingen puts forth some of the most curiously beautiful and theologically sublime Responsories and Antiphons that illustrate this this sacred truth:

  ℟. Hail Mary, O Authoress of life, rebuilding salvation, thou who didst confound death and crushed the serpent toward whom Eve stretched forth, her neck outstretched with the swelling of pride. Thou didst trample on him when thou didst bear the Son of God from heaven: * Whom the Spirit of God breathed forth. ℣. O most tender and loving Mother, hail, thou who bore for the world thy Son sent from heaven. ℟. Whom the Spirit of God breathed forth. (Responsory Ave Maria)

   ℟. O most radiant Mother of sacred medicine, thou didst pour forth ointment through thy holy Son on the sobbing wounds of death that Eve built into torments for souls. Thou didst destroy death, building life: * Pray for us to thy Son, O Mary, Star of the Sea. ℣. O vivifying instrument and joyful ornament and sweetest of all delights, which in thee shall never fail. ℟. Pray for us to thy Son, O Mary, Star of the Sea. (Responsory O clarissima Mater)

   ℟. O most resplendent Jєωel and unclouded beauty of the Sun that was poured into thee, a Fountain springing from the Father’s heart, which is His only Word, through which He created the prime matter of the world: * Which Eve threw into confusion. ℣. Unto thee the Father fashioned this Word as man, and therefore thou art that luminous matter through which this very Word breathed forth all virtues, as in the prime matter He brought forth all creatures. ℟. Which Eve threw into confusion. (Responsory O splendidissima gemma)

   Today a closed gate hath been opened to us, that which the serpent choked in a woman, hence the flower of the Virgin Mary gleams in the dawn. (Antiphon Hodie aperuit)

   Therefore, because a woman constructed death, a bright Virgin hath demolished it, and so the supreme blessing is in feminine form above all creation, because God hath become man in the most sweet and blessed Virgin. (Antiphon Quia ergo femina)

Wherefore, did the Angel in saluting the Blessed Virgin, “Ave, gratia plena” (S. Luke i. 28): “from Eva he formed Ave, the name of Eve being reversed,” as Adam of St. Victor wrote (“Ex Eva format Ave, / Evæ verso nomine,” Sequentia XLV Annunciatio Beatæ Mariæ Virginis; The Liturgical Poetry of Adam of St. Victor [trans. Digby S. Wrangham; London: Kegan Paul, Trench, & Co., 1881]). The renowned Hymn Ave, maris stella prays to the Sacred Virgin, “Establish us in peace, receiving that Ave from the mouth of Gabriel, changing Eve’s name” (“Sumens illud Ave / Gabrielis ore, / Funda nos in pace, / Mutans Hevæ nomen”). The celebrated treatise The Myroure of Oure Ladye explains the mystical significance of the reversal of Eve’s name:  

[This salutation] was the beginning of our health. And therefore this word Ave spelled backward is Eva for like as Eve’s talking with the fiend was the beginning of our perdition so our Lady’s talking with the angel when he greeted her with this Ave was the entrance of our redemption.

In her Immaculate Conception did Mary Most Holy overcome the sin and malediction of Eve as defined in the Bull Ineffabilis Deus of the Supreme Pontiff, Pope Pius IX of venerable memory. Her Nativity was indeed a most joyous portent of our Redemption.

The Virgins of the Order of Saint Savior, who dedicate Wednesdays to honor the Nativity of Blessed Mary the Virgin, congratulate Saint Anne in a very beautiful Responsory found in the Bridgettine Breviary, for having brought forth unto the world such a felicitous grace:

  ℟. O blessed Mother Anne, thou coffer of the eternal King, Who in thee hath hidden a Treasure most well-pleasing unto Him, wherewith He hath endowed His only-begotten Son, enriched the poor: * And ransomed the wretched captives.
   ℣. O venerable Mother, do thou rejoice on account of thy most venerable Daughter, who as Virgin hath brought forth Him Who hath created all things, * And ransomed the wretched captives.

The children of St. Benedict also congratulate this holy Matron in the following Responsory found in the Office for the 26th of July in the Breviarium Monasticuм, wherein they honor both Sts. Anne and Joachim with a proper Office:

  ℟. O venerable Anne, noble and marvelously salutary is thy fruit, the Virgin Mary: * The Mother of the Lord, the comfort of the world, the refreshment of the weary, and the hope of wretches.
   ℣. Rejoice and be gladdened, O blessed mother, for thy Daughter is * The Mother of the Lord, the comfort of the world, the refreshment of the weary, and the hope of wretches.

Likewise do they offer devout felicitations in the same Office to holy Patriarch who begot the Immaculate Virgin:

  ℟. O happy Joachim, thou hast begotten a Daughter who shall bring forth the Savior of the world: * Do thou rejoice, and do thou offer for us prayers before the Queen of the heavens.
   ℣. O happy father of a still happier Daughter, who of herself alone hath brought forth the only-begotten Son of God. * Do thou rejoice, and do thou offer for us prayers before the Queen of the heavens.

Indeed, exceedingly blessed were these holy souls, Sts. Anne and Joachim, whom the Lord had predestined to bring forth the great Mother of God, a birth of such splendor and joy, depicted in beautiful sidereal imagery in a Responsory found in the Carmelite Breviary:

  ℟. To bring forth the supreme King, the Sun of justice, * Mary, the Star of the sea, has gone forth this day unto her rising.
   ℣. O rejoice ye faithful to behold the divine Light: * Mary, the Star of the sea, has gone forth this day unto her rising.

Other Responsories in the Carmelite Breviary avail themselves of beautiful botanical imagery to depict the ineffable prodigy of the Nativity of the Blessed Virgin Mary:

  ℟. At the good-pleasure of the Lord enriching our honor, * Jєωry hath brought forth Mary like unto a thorn bringing forth the rose.
   ℣. So that virtue may overcome vice and grace may triumph over sin, * Jєωry hath brought forth Mary like unto a thorn bringing forth the rose.

   ℟. The rod of Jesse hath produced a branch, and the branch a Flower: * And upon this Flower hath the life-giving Spirit rested.
   ℣. The Virgin Mother of God is the branch, the Flower is her Son. * And upon this Flower hath the life-giving Spirit rested.

The Blessed Virgin herself, as St. Augustine notes, joyfully praises her Divine Son in an everlasting Magnificat for the plenitude of glory and grace to which He has vouchsafed to predestine her out of the infinite and eternal abundance of His inexhaustible charity:

Let Mary now make a loud noise upon the organ, and between its quick notes let the rattling of the Mother's timbrel be heard. Let the gladsome choirs sing with her, and their sweet hymns mingle with the changing music. Hearken to what a song her timbrel will make accompaniment. She saith: ‘My soul doth magnify the Lord, and my spirit hath rejoiced in God my Savior. For He hath regarded the lowliness of His hand-maiden, for, behold, from henceforth all generations shall call me blessed—for He That is Mighty hath done to me great things.’ The new miracle of Mary's delivery hath effaced the curse of the frail backslider, and the singing of Mary hath silenced the wailing of Eve.

O that each one of us would cooperate with the graces that are given to us all at every moment of our terrestrial exile, so that we may persevere in the cultivation of the interior life so as to attain to a happy death that may lead us to perpetual beatitude wherein we may accompany with our praises this ineffably beautiful and joyous Magnificat that the glorious Queen of Angels endlessly intones before the throne of her Divine Son, presenting Him the adoration and thanksgiving of the souls for whose sakes He had deigned to become a little Infant in her immaculate womb. This very grace our beloved Mother and Queen is most desirous to bestow upon us through her unfailing patronage and tutelage, despite our demerits―more so than we are desirous in attaining thereto― and so, “Let us go with confidence to the throne of grace, that we may obtain mercy and find grace in seasonable aid” (Heb. cap. iv., 16), that is, let us have recourse unto Mary always and everywhere.[/font][/color][/size][/b]

Note: This is posted early perchance the exigencies of duty and circuмstance do not permit me to post it in a timely manner...

I thought that the feast of the Nativity of the Blessed Virgin was September 8.

Happy Birthday, Blessed Virgin Mary! I love you very much.