From Longman Dictionary of Contemporary Englishlike clockworklike clockwork (also (as) regular as clockwork)REGULAR happening at the same time and in the same way every time Matt came round each Friday, regular as clockwork. → clockwork
Examples from the Corpus
like clockwork• At 6:30 every evening, like clockwork, Ari went out to milk the cows.• The charity event was well organized and ran like clockwork. 