Passing default values in the View

Hello Everyone,

Kindly let me know how I can pass default values esp current date time to input parameters in the view

I am referring the CAP documentation but unable to find the syntax for passing the default value to the input parameter

entity SomeView ( someDate: datetime default $now )
as SELECT * from Employees where joiningDate <= : someDate;

Thanks in advance.

Regards,

Sandeep