Wiktionary
adv. hourly, beginning at the start of each hour.
Wikipedia
On the Hour was a British radio programme that parodied current affairs broadcasting, broadcast on BBC Radio 4 between 1991 and 1992.
Written by Chris Morris, Armando Iannucci, Steven Wells, Andrew Glover, Stewart Lee, Richard Herring and David Quantick, On the Hour starred Morris as the overzealous and self-important principal anchor (for which he used his own full name). He was accompanied by a regular cast assembled by Iannucci, comprising Steve Coogan, Rebecca Front, Doon Mackichan, Patrick Marber and David Schneider, who portrayed assorted news reporters, presenters and interviewees. On the Hour featured the first appearance of Coogan's character Alan Partridge as the "Sports Desk" reporter.
Usage examples of "on the hour".
Those days in which the sun rose and set every hour on the hour, striping the planet in yellow and black.
Every hour on the hour the deputy director for operations of the CIA called for an update on his progress, always ending their conversations with the same terse warning not to share the information with anyone.
And if the Samuel Claggert Memorial Private Museum (Guided Tours on the Hour -- Admission $1.
Return to your home and listen to telephoned orders every hour on the hour!
Curses on the hour that she came into the world: curses upon her that she make not away with herself, basest, most faithless of women that she must needs be, the reproach of her sex, the opprobrium of all the ladies of this city, to cast aside all regard for her honour, her marriage vow, her reputation before the world, and, lost to all sense of shame, to scruple not to bring disgrace upon a man so worthy, a citizen so honourable, a husband by whom she was so well treated, ay, and upon herself to boot!