How to refer to times with two zeros, such as: 1:00, 2:00, 3:00 etc. (excludes hours with minutes such as 1:01, 2:01, 3:10 etc.)?

Should I refer to them as "completed hours" / "closed hours"/ "round hour" /"rounded hour / whole hour?

I want to say, for example, that such times (01:00, 02:00, 03:00 etc.) are said easily as they are not mixed with minutes.

  • "In two hours" is not specifying a time of day, it is specifying an interval from now. It's like the difference between saying "thirty miles North of here" against "at map location 52.134 degrees North, 1.257 degrees West". Your question seems to be about times of day, but referring to these as "hours" rather than "times" will confuse many English speakers.
    – Colin Fine
    Mar 25, 2018 at 10:35
  • As you yourself said in your other question, these times (not "hours", unless you want to confuse English speakers) are "one o'clock", "two o'clock" etc. I'm not sure what you are asking that is different.
    – Colin Fine
    Mar 25, 2018 at 10:38
  • I really didn't know that. Now I learnt it from you and edited my question. I found the meaning on Cambridge dictionary: "a particular point in the day, as expressed in hours and minutes or shown on a clock, or a particular point in time." dictionary.cambridge.org/dictionary/english/time Mar 25, 2018 at 10:51

2 Answers 2


If you mean that you want to emphasize that something occurs right at the time XX:00 consider using the phrase "on the hour". For example:
"Trains from New York to Philadelphia depart every hour, on the hour".


It is called "top of the hour".

Top of the hour: "The beginning of any or each of the twenty-four divisions of the day; noon, 1:00, 2:00, etc.: news is broadcast at the top of the hour." (Webster's New World College Dictionary, 5th Edition)

It is opposite to each half hour (such as: 1:30, 2:30, 3:30 etc.) that is called: "the bottom of the hour"-

the bottom of the hour: Half-past the hour (such as 12:30, 3:30, etc.)." (Farlex Dictionary of Idioms. ©2015)

  • "Top of the hour" is not idiomatic for me. I vaguely recognise it, and think of it as something that a radio announcer in rural America might say - not something I would expect to hear used seriously. (This might be a UK/US difference). "The bottom of the hour" I have never heard, and would probably not have understood if I had heard it.
    – Colin Fine
    Mar 25, 2018 at 11:15
  • So now that you understand clearly what I mean, what do you suggest to replace it with, in a way that people in the UK will understand me immediately? (the top of the hour) Mar 25, 2018 at 11:22
  • 1
    @ColinF - Not just rural America, but this terminology is not all that uncommon in U.S. media. One place I hear this often is in live national radio news programs. Because the country spans four time zones, it’s easier to use vague expressions like “the top of the hour” or “ten minutes past the hour” than it is to say, “9 o’clock Eastern, 6 o’clock Pacific”, since most listeners likely already know the hour and therefore only need to know the minutes.
    – J.R.
    Mar 25, 2018 at 11:56
  • @J.R. at these places that you expect to hear a use of "the top of the hour" it would be OK to say "They are there at each top of an / the hour" or "There is a show at each top of on/ the hour"? Mar 25, 2018 at 12:02
  • @Archimedean_Point - Not “an”, but “the” (or maybe “every”). And they probably would not say “a show”, but something more specific. For example: “Tune in for the news at the top of every hour.” Another expression that’s made it’s way into US radio is “on the eights” (or nines, or fours), as in, “Get your traffic on the eights”, which means the radio station will issue a traffic report at 7:08, 7:18, 7:28, etc. I typically only hear this in bigger cities that have traffic heavy enough to warrant such frequent updates.
    – J.R.
    Mar 25, 2018 at 12:07

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .