I am not sure what kind of curry sauce you mean. Can you be more specific?

Oh, maybe it was just me, as we have curry sauces in Germany that are sort of like tomato ketchup etc, too. (As curry the spice rather than the dish)

Anyway, if it's the thick paste that you mix with the coconutmilk etc. in a curry, that keeps in the fridge for a really long time. The spices and oil preserve it quite well. Couldn't give you a specific time span, but I had both red and green curry paste in the fridge for several months (then it was used up, so I don't know when it would go). It was stuff from a jar though. If you make you're own it should still be good for some weeks in the fridge in an airtight container.

I am not sure if I that answers your question. But hope I was of some help at least...