be as regular as clockwork

To happen at predictable intervals. My daughter starts crying every night at bedtime—it's as regular as clockwork.

if something is as regular as clockwork, it happens at exactly regular times Her letters arrived every week, regular as clockwork.

Name	Pronounced	Usage
Obdulia	-	Spanish
Mairenn	-	Irish
Lexus	LEKS-əs	English
Chifuniro	-	Southern African, Chewa
Gytha	-	English (Archaic)
Havilah	HAV-i-lə (English)	Biblical