We know that in Acts the Apostles prayed in the upper room consecutively until the Holy Spirit descended on them. Oftentimes I heard that this was calculated to be for nine days. How did people reach this number?
How long did the apostles devote themselves to prayer in Acts 1:14?
It may be possible the term "novena" comes fromActs1: 12,14. But it is impossible to know for sure.
Succinctly, a novena is a nine day period of private or public prayer to obtain special graces, to implore special favors, or make special petitions. (Novena is derived from the Latin novem, meaning nine.) As the definition suggests, the novena has always had more of a sense of urgency and neediness.
The origin of the novena in our Church’s spiritual treasury is hard to pinpoint. The Old Testament does not indicate any nine-days celebration among the Jewish people. On the other hand, in the New Testament at the Ascension scene, our Lord gives the apostles the Great Commission, and then tells them to return to Jerusalem and to await the coming of the Holy Spirit. Acts of the Apostles recounts, “After that they returned to Jerusalem from the mount called Olivet near Jerusalem– a mere Sabbath’s journey away. Together they devoted themselves to constant prayer” (Acts 1:12,14). Nine days later, the Holy Spirit descended upon the Apostles at Pentecost. Perhaps, this “nine-day period of prayer” of the apostles is the basis for the novena. - What is a novena?
In fact Novenas to the Holy Spirit are starting to become more popular between Ascension Thursday and Pentecost Sunday. Thus if one counts the days between these two great ecclesial days there are exactly nine days from Friday to the following Saturday inclusive.
The novena to the Holy Spirit is the prototype of all novenas (nine days of prayer) because, in a sense, it was instituted by Christ himself when he sent his apostles back to Jerusalem to await in prayer the coming of the Holy Spirit. The nine days span the time between Ascension Thursday (celebrated on Sunday in the United States) and Pentecost Sunday.
As the Lord had instructed, after his Ascension into heaven the apostles returned to Jerusalem, entered the upper room, and “all these devoted themselves with one accord to prayer, together with some women, and Mary the mother of Jesus, and his brothers…And suddenly there came from the sky a noise like a strong driving wind, and it filled the entire house in which they were. Then there appeared to them tongues as of fire, which parted and came to rest on each one of them. And they were all filled with the Holy Spirit and began to speak in different tongues, as the Spirit enabled them to proclaim” (Acts 1:14; 2: 2-4).
These events mark the first Pentecost, when the Holy Spirit whom Jesus had promised came down with power, revealing his divine personhood, and gave the disciples the gifts necessary to carry out their mission from Jesus to “go and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit, teaching them to observe all that I have commanded you” (Mt. 28:19f). Pentecost is spoken of as the “birthday” of the Church.
Like the first disciples, all of us are called by Baptism and Confirmation to “speak in different tongues,” to bring the good news of the Gospel to everyone. The Church in our day is called to be renewed in this mission. If we live in hope of a new Pentecost in our time, then we must pray to the ‘principle agent of evangelization, the Holy Spirit.’
The following novena is based on traditional prayers, and is centered on the gifts associated with the Holy Spirit (wisdom, understanding, counsel, fortitude, knowledge, piety and fear of the Lord). These form a supernatural framework through which the Holy Spirit moves us from within, by conforming us to the very mode of his own action. Also reflected in the novena are the so-called “fruits” or perfections that the Holy Spirit forms in us as a pledge of eternal glory. These are charity, joy, peace, patience, kindness, goodness, generosity, gentleness, faithfulness, modesty, self-control and chastity. Both the gifts and fruits of the Holy Spirit are ordered to the mission we have as baptized Christians to live and proclaim our new life in Christ.
The Catechism of the Catholic Church states: “The traditional form of petition to the Holy Spirit is to invoke the Father through Christ our Lord to give us the Consoler Spirit. Jesus insists on this petition to be made in his name at the very moment when he promises the gift of the Spirit of Truth. But the simplest and most direct prayer is also traditional, ‘Come, Holy Spirit,’ and every liturgical tradition has developed it in antiphons and hymns” (no. 2671). Novena to the Holy Spirit
The existing answers give much valuable and interesting information. This is just to indicate, as asked, how the number of days is actually calculated.
Leviticus 23 16 gives the date of the Jewish Festival of Pentecost as occurring fifty days after the Passover Sabbath. On the basis that the Jewish Passover began on the evening of Good Friday then Pentecost was the Sunday 7 weeks after Easter Day,
This question on the Judaism stack exchange has more about this.
Acts 1 verse 3 tells us that the risen Jesus was seen by His apostles for a period of forty days. Beginning on Easter Sunday, as the first day, we get that the fortieth day was a Thursday, which the Church celebrates as Ascension Day. (In practice it is often celebrated on the following Sunday for convenience.)
Acts 2 verse 1 tells us that the Holy Spirit came on the Day of Pentecost, that is on the Sunday ten days after the Ascension of Christ. This is why Whit Sunday, or Christian Pentecost, is always exactly 7 weeks after Easter Day.
This leaves the intervening days between Ascension Day and Whit Sunday on which the apostles prayed, as the Friday and Saturday after the Ascension and the whole of the following week, that is nine days in all.
How long did the Apostles devote themselves in prayer in Acts1:14?
The answer is Nine Days symbolizing the Latin word "novena".
How did the people reach the number of days as nine? Since the scriptures is silent, the Sacred Tradition will play an important role as the Church is a depository of Truth about the faith of the Church from Apostolic to Church Fathers teachings handed thru Sacred Tradition. (1Timothy3:15 )
The Catholic Church recognized the Novena to the Holy Spirit as the first novena prayer as Jesus is the one who instructed the Apostles to wait for the coming of the "another Advocate" and the "Spirit of Truth" in John14:16.
The Catholic Church associated the nine days prayer to the following,
" Overtime, members of the Roman Catholic faith began to associate novena with Christian themes such as the nine months of Jesus spent in the womb, the giving up of His spirit at the ninth hour, and the event occured in the Upper Room with Twelve Apostles and the Blessed Virgin Mary when they prayed for nine days until the Holy Spirit descended on the Feast of the Pentecost.
In the New Testament this biblical event is often quoted from Acts1:12 - 2:5. The Church Fathers also assigned special meaning to the number nine, seeing it as a symbolic of imperfect man turning to God in prayer. ( due to its proximity with the number ten, a symbolic of perfection and God) https://en. m. wikipedia. org
The mysterious question is who lead the Apostles to a novena prayer invoking the Holy Spirit to come. Nobody among all the Apostles knew the manifestation of the Holy Spirit and most especially how to prepare the Apostles heart to become the temple of the Holy Spirit.
The Pentecost also will reveal who is the "another Advocate" and the "Spirit of Truth". The Holy Spirit will anoint all the Apostles & Disciples to testify to the Truth of who Jesus is, to spread the gospel of Christ.
Book of Acts describes all who received the anointing appear to be drunk? Did the Apostles celebrate the First Holy Mass in the Upper Room and eat & drink the "bread & wine"?
The prayer of the Apostles in the Upper Room was only possible by the intercession of the Theotokos as She is the only person who experienced the overshadowing of the Holy Spirit and can lead the Apostles to Novena prayer.
And since the Holy Spirit anointing will impart wisdom to all the Apostles, the heart of all the Apostles must resemble the heart of Mary as wisdom will not dwell in a body subjects to sins:
Jesus breathing initially the Holy Spirit in ( John 20:22-23 ) gave all the Apostles the power to forgive sins, to prepare their hearts to celebrate the First Holy Mass in the Upper Room and be worthy to partake the Holy Eucharist.
" For wisdom will not enter into malicious soul, nor dwell in a body subject to sins. " (Wisdom 1:4 )