Is it ok to put a slow cooker on a timer?

[alrightfella]

Unexpectedly busy today coming up tomorrow. Last one out of the house at 8, first one back at 5.

Would it be ok if I put a load of tomatoes and onions in the slow cooker and then put on a timer plug to come on at 12? Just thinking it would be an easy pasta sauce.

I usually make it in the oven on a low heat for a couple of hours. Would I need to precook the onions do you think?

Yes it's fine to put it on a timer - I often do.
Don't think you'd need to pre-cook the onions unless you want that caramelised-type taste as obviously that will make a bit of a difference.

If it's just veg that will be OK.