=CNUM(JOUR(SERIE.JOUR.OUVRE(A10+B10;ENT(C10/8);Feries!$A$2:$A$14)+CNUM((HEURE(A10+B10)+MOD(C10;8))&":00"))&"/"&MOIS(SERIE.JOUR.OUVRE(A10+B10;ENT(C10/8);Feries!$A$2:$A$14)+CNUM((HEURE(A10+B10)+MOD(C10;8))&":00"))&"/"&ANNEE(SERIE.JOUR.OUVRE(A10+B10;ENT(C10/8);Feries!$A$2:$A$14)+CNUM((HEURE(A10+B10)+MOD(C10;8))&":00")))
=CNUM(HEURE(SERIE.JOUR.OUVRE(A10+B10;ENT(C10/8);Feries!$A$2:$A$14)+CNUM((HEURE(A10+B10)+MOD(C10;8))&":00"))&":")
=ENT(GAUCHE(M10;10))