I will start with the fact i love a good roast, and i know logically you can have one any time,BUT it seems odd to eat one on a Saturday night for some reason.
Apart from the fact i like a roast, another benefit it brings is that i can prepare most of it in advance so it still enables me to drop kids to and from their clubs and I know they will also eat it!! Win win
Would you think its a strange choice if you went around for an evening dinner and were served a roast dinner???
Unreasonable- you can not serve a roast for saturday night dinner
Reasonable- stop being silly thats perfectly fine