October 2 is observed as the memorial of the Guardian Angels in the Roman Catholic Church. It is an "obligatory memorial," meaning that it is celebrated each year and is not replaced by another saint.
However, the liturgical rank of this celebration is still one of the lowest, and it is always superseded by the Sunday liturgy.
The main reason why the memorial of the Guardian Angels is typically not celebrated on Sunday is because it does not match the following criteria.
The memorial of the Guardian Angels is not a solemnity, nor is a feast of the Lord.
On the other hand, if a parish church is dedicated to the guardian angels, then the feast will supersede the Sunday liturgy.
Regardless, while the Church may not liturgically celebrate the guardian angels this year, it does not mean Catholics cannot honor their guardian angels and pray to them for protection.