Catechism of the Catholic Church
“The Church obliges the faithful ‘to take part in the Divine Liturgy on Sundays and feast days’ and, prepared by the sacrament of Reconciliation, to receive the Eucharist at least once a year, if possible during the Easter season. But the Church strongly encourages the faithful to receive the holy Eucharist on Sundays and feast days, or more often still, even daily.”
Source: Catechism of the Catholic Church #1389