I remember the JM clock. Its faceplate looked like it was built around a pocket calculator. Batrow had a clock that operated individual mini-relays for each zone. Not surprising for a company whose reputation was made with a clock that toggled a stepping relay.
Best ever clock (NOT!!!) was an ancient Imperial that actually rotated a set of cams you had to adjust one at a time. One cam on. One cam off. Need to add time to one zone? Move the off cam, and then move all the cams for zones that follow, so runtimes don't overlap. Best of all, the clock was all line voltage, and it was very easy to touch a conductor when adjusting cams.