Does “8am” mean 𝒆𝒙𝒂𝒄𝒕𝒍𝒚 08:00:00.000 in the morning, or does it just mean any time closer to that hour than to either 7:00 or to 9:00? [closed]

Suppose I wanted to indicate the range of time from exactly 8:00am to exactly 8:30am. Should I write “8:00am” for explicitness, or is exactly 8:00am implied by “8am”?

Also, is “2:15pm–2:45pm”, for example, an acceptable formatting of such a range, or should I be writing it differently?

(I am using am/pm lowercase with no space which I am near certain is correct, along with an en dash with no spacing, which I am pretty sure is a standard way of writing ranges.)

I was perhaps not specific enough in my first iteration of this question. I am mainly interested in meaning and aesthetics as elaborated upon in my reply to a comment hereunder.

Solution 1:

@MichaelHarvey provided what I consider to be an answer to my question in the comments:

If you have any times which include minutes, express all times that way, using '00' for on-the-hour times.

This built upon a specification by @EdwinAshworth on how precision is implied:

The domain in which you're writing will inform the degrees of accuracy 8:00am and 8am convey.

So now I know that while "8am" could mean exactly 8:00am, "8:00am" should still be used for the sake of being explicit in contexts where precision is not obviously implied, and/or for the sake of aesthetic consistency.