"Regular as clockwork" is an idiomatic expression that refers to something that happens with consistent and predictable timing. There are several synonyms that convey a similar meaning, such as "punctual," "timely," "reliable," and "consistent." "Punctual" implies strict adherence to a schedule and can refer to people or things. "Timely" suggests a sense of urgency and importance in meeting a deadline. "Reliable" denotes a trustworthy and dependable quality. "Consistent" means something that occurs in the same way over a period of time and can be relied upon to happen predictably. These synonyms convey a sense of stability and dependability, qualities that are highly valued in both personal and professional contexts.