Dynamic effective date on Analysis

Summary:

I am trying to get active employees as of a future date in Analysis "Workforce Management - Worker Assignment Real Time"

Content (required):

I am able to use a static date with the format YYYY-MM-DD in prefix to set a future date, but I wanted a dynamic value so I set the prefix as "SET VARIABLE PARAM_EFFECTIVE_DATE = '@{P_DATE}{@{system.currentTime}[YYYY-MM-DD]}';" and it worked. But to have a future date in dynamically hasn't worked. So I set a presentaion variable with SQL reaults query as (select timestampadd(SQL_TSI_DAY,10,CURRENT_DATE) from "Workforce Management - Worker Assignment Event Real Time") and the prefix as "SET VARIABLE PARAM_EFFECTIVE_DATE='{@{AsOfDate}[YYYY-MM-DD]}';" and it din't work.