=(SI(ESTERR(CHERCHE("January";B2));"";SUBSTITUE(DROITE(B2;NBCAR(B2)-CHERCHE(" ";B2));"January";"janvier"))
&SI(ESTERR(CHERCHE("February";B2));"";SUBSTITUE(DROITE(B2;NBCAR(B2)-CHERCHE(" ";B2));"February";"février"))
&SI(ESTERR(CHERCHE("March";B2));"";SUBSTITUE(DROITE(B2;NBCAR(B2)-CHERCHE(" ";B2));"March";"mars"))
&SI(ESTERR(CHERCHE("April";B2));"";SUBSTITUE(DROITE(B2;NBCAR(B2)-CHERCHE(" ";B2));"April";"avril"))
&SI(ESTERR(CHERCHE("May";B2));"";SUBSTITUE(DROITE(B2;NBCAR(B2)-CHERCHE(" ";B2));"May";"mai"))
&SI(ESTERR(CHERCHE("June";B2));"";SUBSTITUE(DROITE(B2;NBCAR(B2)-CHERCHE(" ";B2));"June";"juin"))
&SI(ESTERR(CHERCHE("July";B2));"";SUBSTITUE(DROITE(B2;NBCAR(B2)-CHERCHE(" ";B2));"July";"juillet"))
&SI(ESTERR(CHERCHE("August";B2));"";SUBSTITUE(DROITE(B2;NBCAR(B2)-CHERCHE(" ";B2));"August";"août"))
&SI(ESTERR(CHERCHE("September";B2));"";SUBSTITUE(DROITE(B2;NBCAR(B2)-CHERCHE(" ";B2));"September";"septembre"))
&SI(ESTERR(CHERCHE("October";B2));"";SUBSTITUE(DROITE(B2;NBCAR(B2)-CHERCHE(" ";B2));"October";"octobre"))
&SI(ESTERR(CHERCHE("November";B2));"";SUBSTITUE(DROITE(B2;NBCAR(B2)-CHERCHE(" ";B2));"November";"novembre"))
&SI(ESTERR(CHERCHE("December";B2));"";SUBSTITUE(DROITE(B2;NBCAR(B2)-CHERCHE(" ";B2));"December";"décembre"))
)+0