Date parameters through derived table

Hello All,

I am trying to create date parameters at universe using a derived table. This is my sql statement

select trunc(tochar(sysdate,'M/dd/yyyy')) as "Today" from dual

But it says that wrong syntax with trunc.

Can any one suggest the correct syntax for that?

My requirement is to make date parameter objects like today, yesterday, 1 week prior etc.

Reply would be much appreciated.

Regards