If people have a bad day the last thing they want to hear is 'what's wrong'.

They are also not interested in receiving your advices regarding their current problems or proposals how to cheer theirself up.

Instead satysfying your curiosity and feeding yourself with their misery you should rather say 'I'm with you'.

People have right to feel sad.

They also have right to be alone with their sadness if they want to.

And they don't have to cheer, only because their sadness violates your sense of comfort.