Immediately exit a query if a condition is verified - forum topic by gxgxg

Hi to everybody,
I'd like to to this: I have a query which usually takes some minutes to run; this query runs every night; I only need to run the query on Monday, but I can't change the automatic night job of every day. So I'd like to put in the query a trick such that if the day is not Monday it returns 0 rows in just some seconds, while if the day is Monday it executes the query as usual.
I can't use BTEQ.
Is there a way to do that?
Thank you very much in advance.