You can say: Le vendredi costumé or Vendredi le jour du costume, wich is a more word to word translation . I would choose the first one.
this Friday is : 'ce vendredi' in French.
You spell it the same, 'un costume' (masc.)
Vendredi 13 is the French spelling for Friday the 13th. 13 is 'treize' in French.
Vendredi
un costume d'éléphant
des femmes costume
le vendredi
A Chanel suit is "un tailleur Chanel" in French.
c'est vendredi.
heureux, c'est vendredi !
Vendredi 14 septembre
vendredi, sept mars