at all hours (of the day and night)
At any time of the day or night. This phrase is usually said with a note of annoyance because something has happened at an inappropriate time. Please tell your girlfriend to stop calling our house at all hours of the day and night. I haven't slept in days—my neighbor's dog has been barking at all hours.
at ˈall hours
at any time during the night or day; all the time: He comes here at all hours, sometimes in the middle of the night.