In the Catholic Church, holy days of obligation or precepts are days on which the faithful are expected to attend Mass, and engage in rest from work and recreation (i.e., they are to refrain from engaging in work or activities that hinder the worship owed to God), according to the third commandment.
The expectation is attached to the holy day, even if transferred to another date, as sometimes happens in the Roman Rite. However, in some countries a dispensation is granted in such circumstances.[1]