The clock was a District Attorney turned masked vigilante in CMC/Centaur Comics’s Funnies in Late (cover dated November) 1936. He predates Superman, Crimson Avenger and The Spirit. He had about 90 appearances from 1937-44, mostly in Quality Comics “Feature Funnies” and “Crack Comics”.

Despite Quality’s Characters (Most notably Plastic Man, The Blackhawks and Uncle Sam & the Freedom Fighters) getting acquired by National/Detective Comics in 1956, I don’t know of any Clock appearances in DC books aside from some mentions in “Shade’s Journal” text backups in Starman, seems like they prefer to use Quality’s later admitted Spirit knockoff ‘Midnight’.