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If the cat is urinating normally, then you can take him in in the morning, but i would not wait longer than that as he may develop a life threatening urinary obstruction.
If you do not know if he is urinating, or if he is urinating small amounts or going in and out of the letterbox frequently, then the best thing to do is to take him in to the emergency vet tonight as he may have a urinary obstruction and this can be life threatening. If he is vomiting, I would also take him in tonight as this is a sign of urethral obstruction.