rman clone with duplicate database command to till date/ scn.

Dear Team,

I am  taking weekly backup of my database using rman hot backup. and use  the same backup for cloning purpose using the below command.

run {

set until scn < scn number>;                   -- find out the scn no by list backup command on the source database (prod instance)

duplicate target  database to <TEST>;

}

when i performed  the cloning with the above method i get the data till the last backup only.  But I want to get the data  till last date when i performed the cloning process.

kindly suggest me how can i get the latest data on my clone instance after the rman backup.