Is there such a thing? A very quick Google hasn't turned anything up.
What I was thinking I want (though I'm open to having my mind changed) is a wireless doorbell where I can have something downstairs that chimes, and ditto for upstairs. BUT, I would like the upstairs one to avoid chiming in the evening/night while my toddler is (likely to be) asleep. I guess I could get a timer socket, but are there other options?