From Longman Dictionary of Contemporary Englishfestive occasionfestive occasionCELEBRATEa day when you celebrate something special such as a birthday → festive
Examples from the Corpus
festive occasion• The Great Hall had been specially prepared for the festive occasion.• The harvest, or vintage, is a family festive occasion.• It was a festive occasion and the group had baked its own Communion bread.• In Bali a cremation is a festive occasion, lavish and expensive. 