Ordinary Time in the Catholic Church is the largest season of the liturgical year, running for a total of 33 or 34 weeks.
This season is split into two different sections of the year.
Ordinary Time begins following the feast of the Baptism of the Lord in January and typically runs for several weeks, until it is interrupted by the seasons of Lent and Easter.
The season resumes after the celebration of Pentecost and continues uninterrupted until the beginning of Advent.
The exact number of weeks of Ordinary Time depends on when the seasons of Lent and Easter fall each year, as well as the starting date of Advent.
According to Fr. Edward McNamara, the Church may “skip” a week of Ordinary Time to ensure that the readings for the 34th week are always read.
[T]he Church wishes to ensure that the readings for the 34th week of Ordinary Time are always read. In order to achieve this, the Church often omits the week that would naturally precede the resumption of Ordinary Time following Pentecost Sunday…For this reason the actual number of complete or partial weeks of Ordinary Time in any given year is mostly 33 and occasionally 34.
Since the season is split into two sections, most are unaware of the occasional omission of a week to ensure that the 34th week is celebrated properly
Ordinary Time is a beautiful season of the year, highlighting the growth of life in the Spirit and the holiness of the Church’s saints.