Interruptions seem to come every hour.
In fact, they come exactly every hour. Thanks to my offspring, I now have not one but two clocks on which the hours are represented by different species of songbird. When the big hand gets to 12, the clock plays the song of whatever bird is being pointed to by the little hand. At first, it seemed a clever gimmick, the kind of thing that is fun for a while but quickly becomes tiresome. In the beginning, I was startled every time by the birdsong out of nowhere.