I ask if I want to know. If I'm sitting on a bus or a train bored out of my brain its nice to talk to someone about something interesting. And if they say "Eh, it was good" you're back to looking out the window But that said, I don't usually say "How was your day?" Randomly to the person sitting beside me. It usually starts off with them saying, "Fine weather we're having today" or "The public transport system is quite good isn't it?"
My day was a day.. It was nice outside so that was a plus... My evening was better though...good times...