Most used MOTS in last week

i’d like to create a widget whit hot topic on my website.

To do this i need to create a boucle that shows most used MOTS in recent articles (last month or last week).

Now : i’m able to to this whitout a time limit in this way (mots that can define a topic are in the 9 group in my case) :

<BOUCLE_pagina(MOTS) {id_groupe="9"} {compteur articles} {!par compteur_articles}>

How can i add the time filter to this boucle ?

Thanks for your support !

Dimitri