How to set Specific timing

Question

hello friends,

iam creating one application that i want to mail one file to user at every saturday at 7.00pm
iam searching so much code but not find exactly i wrote find saturday find code but cant set specific timing so please expert help me out here im paste only finding day that is saturday

 DateTime dt=new DateTime ();
          
          
            if (dt.DayOfWeek == DayOfWeek.Saturday)
            {
             
               
            }