off and on
Also, on and off.
Intermittently, from time to time. For example, I read his column off and on, or We've been working on the garden all summer, on and off. [Early 1500s]
Also, off again, on again; on again, off again. Uncertain, vacillating, as in Theirs is an off again, on again relationship, or The peace talks are on again, off again. Some believe this term originally referred to minor railroad accidents, where a train went off track and then on again. [Mid-1800s]