Which sentence about on-the-hour times is correct regarding zeros?

• A. Zeros are not required for on-the-hour times.
• B. Zeros are required for on-the-hour times.
• C. Zeros are optional for on-the-hour times only in informal writing.
• D. Zeros must be used for all times.

Answer: (A)

On-the-hour times are moments when the minutes are zero, so you don’t have to spell out the minutes each time. Saying “three o’clock” or “3 o’clock” communicates exactly that the time is on the hour, without needing a 00. In many writing styles, this is perfectly acceptable and common, especially when you’re expressing time in words. If you do use numeric form, some contexts still show 3:00, but you aren’t required to include the zeros—the important point is that the hour alone (often with “o’clock”) conveys the exact on-the-hour time. That’s why zeros are not required for on-the-hour times.