Simply, lunchtime is 12 noon. Exactly right.
So technically, 12AM and 12:30PM is just afternoon, which technically is 12PM. So to avoid confusion, many people do not use 12AM or 12PM, and prefer to use midnight for 12AM and noon for 12PM. So afternoon begins at noon, and runs until evening. So that is how we identify between 12:30AM and 12:30 PM.
The American Heritage Dictionary of the English Language states "By convention, 12 AM denotes midnight and 12 PM denotes noon.
At exactly 12 noon, the Sun is at its highest point in the sky and directly over the meridian. It is therefore neither 'ante' (am) nor 'post' (pm) meridiem. At 12 midnight it also neither am nor pm.
> Simply, lunchtime is 12 noon.
Noon takes a path through Middle and Old English, where nōn denoted the ninth hour from sunrise. That word derives from the Latin nonus, meaning “ninth,” related to novem, the word for the number nine.
Answer: 12 O'clock in the afternoon is pm.
12:00AM is the start of the day, so midnight of the day before. How does the 12 hour clock time format work? The 12 hour clock runs as follows: 12:00AM, 1:00AM….
For example, “Good morning” is generally used from 5:00 a.m. to 12:00 p.m. whereas “Good afternoon” time is from 12:00 p.m. to 6:00 p.m. “Good evening” is often used after 6 p.m. or when the sun goes down.
12am is the exact moment the 12th hour of the morning finishes (am), and similarly for pm. Therefor 12am is midday and pm would start straight after.
The reason a new day starts at 12:00 goes back to ancient Egypt when the day was measured using sundials. The shadow on the face of a sundial tells the time, and the shadow depends on where the sun is in the sky. "When the sun is highest overhead and the shadow goes straight up to the top of the sundial, that's noon.
This is the middle of the day, also called "NOON" (12:00 hours). This is the time from midnight to midday. This is the time from midday (noon) to evening.
Terminology. Afternoon is often defined as the period between noon and evening. If this definition is adopted, the specific range of time varies in one direction: noon is defined as the time when the sun reaching its highest point in the sky, but the boundary between afternoon and evening has no standard definition.
Midday and midnight conventions
It is often said that 12am Monday is midnight on Monday morning and 12pm is midday. This puts all the times beginning with 12 and ending with am in the same one-hour block, similarly with those ending with pm.
Time of the day is divided in two halves (24hour= 12 hours before midday + 12 hours after midday) so the 11 AM is 11th hour before midday as clock strikes 12 again it changes to PM (after midday) so it's 12 PM after 11 AM and 12 AM after 11 PM.
It's all because of the conventions used with the "12-hour clock." 12:00 am is usually taken to mean midnight (and 12:00 pm is noon). At 59 minutes past midnight it is therefore 12:59 am, but a minute later it's 1:00 am.
12 o'clock in the middle of the day; noon: He frequents the restaurant at noontime.
The afternoon is the time of day that starts mid-day and ends in the evening. If you have an afternoon appointment, it's probably some time between 12:00 and 5:00 p.m. It's pretty much agreed that the afternoon begins after noon, or 12:00 p.m., but when the afternoon ends and evening begins is a bit more vague.
It dates back to when there was just solar time. You know, sundials. AM meant ante (before) meridian and PM meant post (after) meridian. Meridian being that the sun was at the place in the sky where it was the highest , i.e., noon.
The start of a day is commonly accepted as roughly the time of the middle of the night or midnight, written as 00:00 or 12:00 am in 24- or 12-hour clocks, respectively.
We associate P.M. with the afternoon and evening. P.M. is an abbreviated term for 'Post Meridiem,' which implies afternoon or after midday. In a 12-hour clock, these are used as time indications centered around noon.
Late- afternoon: 3-6 p.m. Evening: 6-9 p.m. Late at night: Midnight-6 a.m. Toward morning: 3-6 a.m.