戦没せんぼつしゃ追悼ついとう記念きねんであれば
sembotsusha tsuitōkinenhideareba

Noun
Da Copula

The "-eba" conditional form ("if/when…") of 戦没者追悼記念日

1. If it is Memorial Day for the war dead; If it were Memorial Day for the war dead

Ba Conditional