at all hours—continuously, especially at unusual or irregular times:
- His songs are heard everywhere in the country and at all hours.
Cf.: until all hours —(also: until all hours of the night) until very late at night:
- I lived the crazy life of a student—studying until all hours, living in front of my computer, all that.
Note: The expression does not correlate in meaning with the phrase at all times—on all occasions; always:
- The accessibility of Italy upon this side was at all times a matter of anxiety to her rulers.
at any hour—at any time; whenever one chooses:
- The knowledge that he might at any hour be called upon stimulated his studies of his duties.
See also: at any one time / at any time.