Me: What time do you think you'll be home?
Wife: Um, well, first I need to do x, and then I need to go
to y, which will probably take an hour. And then I might
swing by z.
Me: So what time do you think you'll be home?
I am not a boss, but quite opposite. But often find myself answering the same way. And later just putting myself into boss's position find that this was not the best answer. Straight and simple yes/not/[number]/today/now/tomorrow much better. Reserve informal talk to a lunch with boss.