How was your day off?

If you've just come back to work after a public holiday, or if your colleague has had a day off, it's considered friendly to talk about the holiday.

Asking about a day off

How was your day off?
Did you do anything exciting / special?
Did you have a good day yesterday?
Did you get up to anything interesting?

Responding

It was great, thanks!
Wonderful thanks! What about you?
Oh, we didn't do much. Just lazed about.
We visited… / had lunch with / went to / checked out…

Being vague

Oh well, you know. The usual.
Oh, nothing special / nothing out of the ordinary.
The usual same old, same old.