ceremonial occasion vs ceremony

ceremonial occasion and ceremony both are nouns.

Word	Noun	Adjective	Verb	Adverb
ceremonial occasion	Yes	No	No	No
ceremony	Yes	No	No	No

As nouns, ceremonial occasion and ceremony are synonyms defined as:

ceremonial occasion and ceremony: a formal event performed on a special occasion

Other synonyms of ceremonial occasion include ceremonial, observance.

ceremonial occasion (noun)	ceremony (noun)
a formal event performed on a special occasion	the proper or conventional behavior on some solemn occasion
	any activity that is performed in an especially solemn elaborate or formal way
	a formal event performed on a special occasion