You need to use a datetime literal, but I don't think you can use that syntax in SQL as you have no FROM clause.
Here is how to do it with a data step.
data new;
enddt = "&enddt"dt ;
format enddt datetime20.;
run;
To make a literal using SAS you follow the value in quotes with the special letter for the type of literal. Common literals are:
t -> Time
d -> Date
dt -> DateTime
x -> Hexadecimal
b -> Binary