III. When is the Liturgy Celebrated?

From The Catechism of the Catholic Church

1165
When the Church celebrates the mystery of Christ, there is a word that marks
her prayer: “Today!” – a word echoing the prayer her Lord taught her
and the call of the Holy Spirit.³⁴ This “today” of the living
God which man is called to enter is “the hour” of Jesus’ Passover,
which reaches across and underlies all history:

PART TWO: THE CELEBRATION OF THE CHRISTIAN MYSTERY

SECTION ONE THE SACRAMENTAL ECONOMY
- CHAPTER TWO THE SACRAMENTAL CELEBRATION OF THE PASCHAL MYSTERY
  - Article 1 CELEBRATING THE CHURCH’S LITURGY
    - III. When is the Liturgy Celebrated?

From The Catechism of the Catholic Church – rosary.team