 Some but not all solemnities are also holy days of obligation, on which, as on Sundays, Catholics are required to attend Mass and to avoid work and business that hinder divine worship or suitable relaxation of mind and body.All holy days of obligation have the rank of solemnity at least at local level, though not necessarily holding that rank in the General Roman Calendar.With the exception of the solemnities of the Sacred Heart of Jesus, the Annunciation of the Lord and the Birth of John the Baptist, all the solemnities inscribed in the General Roman Calendar are mentioned as holy days of obligation in canon 1246 of the Code of Canon Law, but are not necessarily all observed in a particular country.