ceremonial

US /ˌser.əˈmoʊ.ni.əl/
UK /ˌser.əˈmoʊ.ni.əl/
1.

related to, used in, or involving a ceremony (= a fixed set of formal acts performed on important social or religious occasions):

:
A Marine honor guard flanks the president during ceremonial events at the White House.
1.

(a set of) formal acts, often fixed and traditional, performed on important social or religious occasions:

:
Westminster Abbey is used for ceremonials.