Is there a difference between a Solemn Feast Day and a Holy-day of Obligation?
Yes. At one time, all solemn feasts were obligatory, and in Ukraine many people still observe them as if they were. Western society does not make allowances so many religious holidays, so the Church, using the Power of the Keys, removed the obligation from all except four of the Solemn Feast days. Annunciation, Ascension, Peter-& -Paul, Dormition are designated Holy days of obligation, as are all Sundays.
