When the Johnson triplets were three weeks old, their sleep habits were remarkably consistent. John slept for 3 hours and was awake for 30 minutes. Joan slept for 2 hours and was awake for 30 minutes. Jane slept for 2 hours, 20 minutes and was awake for 40 minutes. On October 13 at 8:00 p.m., they all went to sleep at the same time. When did they go to sleep at the same time again? Give both the date and the time.
(Source: Adapted from Mathematics Teaching in the Middle School, Sep 1997)
